diff --git a/mypyc/annotate.py b/mypyc/annotate.py
index 6736ca63c9e8..bc282fc3ea6c 100644
--- a/mypyc/annotate.py
+++ b/mypyc/annotate.py
@@ -77,6 +77,7 @@ def __init__(self, message: str, priority: int = 1) -> None:
     "PyNumber_Rshift": Annotation('Generic ">>" operation.'),
     "PyNumber_Invert": Annotation('Generic "~" operation.'),
     "PyObject_Call": Annotation("Generic call operation."),
+    "PyObject_CallObject": Annotation("Generic call operation."),
     "PyObject_RichCompare": Annotation("Generic comparison operation."),
     "PyObject_GetItem": Annotation("Generic indexing operation."),
     "PyObject_SetItem": Annotation("Generic indexed assignment."),
diff --git a/mypyc/irbuild/ll_builder.py b/mypyc/irbuild/ll_builder.py
index a5e28268efed..b12bbc0f4f09 100644
--- a/mypyc/irbuild/ll_builder.py
+++ b/mypyc/irbuild/ll_builder.py
@@ -138,6 +138,7 @@
     generic_ssize_t_len_op,
     py_call_op,
     py_call_with_kwargs_op,
+    py_call_with_posargs_op,
     py_getattr_op,
     py_method_call_op,
     py_vectorcall_method_op,
@@ -183,7 +184,12 @@
     str_ssize_t_size_op,
     unicode_compare,
 )
-from mypyc.primitives.tuple_ops import list_tuple_op, new_tuple_op, new_tuple_with_length_op
+from mypyc.primitives.tuple_ops import (
+    list_tuple_op,
+    new_tuple_op,
+    new_tuple_with_length_op,
+    sequence_tuple_op,
+)
 from mypyc.rt_subtype import is_runtime_subtype
 from mypyc.sametype import is_same_type
 from mypyc.subtype import is_subtype
@@ -788,6 +794,26 @@ def _construct_varargs(
         for value, kind, name in args:
             if kind == ARG_STAR:
                 if star_result is None:
+                    # fast path if star expr is a tuple:
+                    # we can pass the immutable tuple straight into the function call.
+                    if len(args) == 1:
+                        # fn(*args)
+                        if is_list_rprimitive(value.type):
+                            value = self.primitive_op(list_tuple_op, [value], line)
+                        elif not is_tuple_rprimitive(value.type):
+                            value = self.primitive_op(sequence_tuple_op, [value], line)
+                        return value, None
+                    elif len(args) == 2 and args[1][1] == ARG_STAR2:
+                        # fn(*args, **kwargs)
+                        if is_tuple_rprimitive(value.type):
+                            star_result = value
+                        elif is_list_rprimitive(value.type):
+                            star_result = self.primitive_op(list_tuple_op, [value], line)
+                        else:
+                            star_result = self.primitive_op(sequence_tuple_op, [value], line)
+                        continue
+                        # elif ...: TODO extend this to optimize fn(*args, k=1, **kwargs) case
+                    # TODO optimize this case using the length utils - currently in review
                     star_result = self.new_list_op(star_values, line)
                 self.primitive_op(list_extend_op, [star_result, value], line)
             elif kind == ARG_STAR2:
@@ -885,9 +911,11 @@ def _construct_varargs(
             # tuple. Otherwise create the tuple from the list.
             if star_result is None:
                 star_result = self.new_tuple(star_values, line)
-            else:
+            elif not is_tuple_rprimitive(star_result.type):
+                # if star_result is a tuple we took the fast path
                 star_result = self.primitive_op(list_tuple_op, [star_result], line)
-        if has_star2 and star2_result is None:
+        if has_star2 and star2_result is None and len(star2_keys) > 0:
+            # TODO: use dict_copy_op for simple cases of **kwargs
             star2_result = self._create_dict(star2_keys, star2_values, line)
 
         return star_result, star2_result
@@ -912,13 +940,16 @@ def py_call(
         if arg_kinds is None or all(kind == ARG_POS for kind in arg_kinds):
             return self.call_c(py_call_op, [function] + arg_values, line)
 
-        # Otherwise fallback to py_call_with_kwargs_op.
+        # Otherwise fallback to py_call_with_posargs_op or py_call_with_kwargs_op.
         assert arg_names is not None
 
         pos_args_tuple, kw_args_dict = self._construct_varargs(
             list(zip(arg_values, arg_kinds, arg_names)), line, has_star=True, has_star2=True
         )
-        assert pos_args_tuple and kw_args_dict
+        assert pos_args_tuple
+
+        if kw_args_dict is None:
+            return self.call_c(py_call_with_posargs_op, [function, pos_args_tuple], line)
 
         return self.call_c(py_call_with_kwargs_op, [function, pos_args_tuple, kw_args_dict], line)
 
@@ -1117,8 +1148,7 @@ def native_args_to_positional(
                 assert star_arg
                 output_arg = star_arg
             elif arg.kind == ARG_STAR2:
-                assert star2_arg
-                output_arg = star2_arg
+                output_arg = star2_arg or self._create_dict([], [], line)
             elif not lst:
                 if is_fixed_width_rtype(arg.type):
                     output_arg = Integer(0, arg.type)
diff --git a/mypyc/primitives/generic_ops.py b/mypyc/primitives/generic_ops.py
index 54510d99cf87..3823d6021d40 100644
--- a/mypyc/primitives/generic_ops.py
+++ b/mypyc/primitives/generic_ops.py
@@ -307,6 +307,15 @@
     error_kind=ERR_MAGIC,
 )
 
+# Call callable object with positional args only: func(*args)
+# Arguments are (func, *args tuple).
+py_call_with_posargs_op = custom_op(
+    arg_types=[object_rprimitive, object_rprimitive],
+    return_type=object_rprimitive,
+    c_function_name="PyObject_CallObject",
+    error_kind=ERR_MAGIC,
+)
+
 # Call method with positional arguments: obj.method(arg1, ...)
 # Arguments are (object, attribute name, arg1, ...).
 py_method_call_op = custom_op(
diff --git a/mypyc/primitives/tuple_ops.py b/mypyc/primitives/tuple_ops.py
index d95161acf853..f262dec8b05a 100644
--- a/mypyc/primitives/tuple_ops.py
+++ b/mypyc/primitives/tuple_ops.py
@@ -76,7 +76,7 @@
 )
 
 # Construct tuple from an arbitrary (iterable) object.
-function_op(
+sequence_tuple_op = function_op(
     name="builtins.tuple",
     arg_types=[object_rprimitive],
     return_type=tuple_rprimitive,
diff --git a/mypyc/test-data/irbuild-basic.test b/mypyc/test-data/irbuild-basic.test
index 4a7d315ec836..7037f430e846 100644
--- a/mypyc/test-data/irbuild-basic.test
+++ b/mypyc/test-data/irbuild-basic.test
@@ -1674,26 +1674,20 @@ def g():
     r0 :: tuple[int, int, int]
     r1 :: dict
     r2 :: str
-    r3 :: object
-    r4 :: list
-    r5, r6 :: object
-    r7 :: tuple
-    r8 :: dict
-    r9 :: object
-    r10 :: tuple[int, int, int]
+    r3, r4 :: object
+    r5 :: tuple
+    r6 :: object
+    r7 :: tuple[int, int, int]
 L0:
     r0 = (2, 4, 6)
     r1 = __main__.globals :: static
     r2 = 'f'
     r3 = CPyDict_GetItem(r1, r2)
-    r4 = PyList_New(0)
-    r5 = box(tuple[int, int, int], r0)
-    r6 = CPyList_Extend(r4, r5)
-    r7 = PyList_AsTuple(r4)
-    r8 = PyDict_New()
-    r9 = PyObject_Call(r3, r7, r8)
-    r10 = unbox(tuple[int, int, int], r9)
-    return r10
+    r4 = box(tuple[int, int, int], r0)
+    r5 = PySequence_Tuple(r4)
+    r6 = PyObject_CallObject(r3, r5)
+    r7 = unbox(tuple[int, int, int], r6)
+    return r7
 def h():
     r0 :: tuple[int, int]
     r1 :: dict
@@ -1704,9 +1698,8 @@ def h():
     r6 :: ptr
     r7, r8 :: object
     r9 :: tuple
-    r10 :: dict
-    r11 :: object
-    r12 :: tuple[int, int, int]
+    r10 :: object
+    r11 :: tuple[int, int, int]
 L0:
     r0 = (4, 6)
     r1 = __main__.globals :: static
@@ -1720,10 +1713,9 @@ L0:
     r7 = box(tuple[int, int], r0)
     r8 = CPyList_Extend(r4, r7)
     r9 = PyList_AsTuple(r4)
-    r10 = PyDict_New()
-    r11 = PyObject_Call(r3, r9, r10)
-    r12 = unbox(tuple[int, int, int], r11)
-    return r12
+    r10 = PyObject_CallObject(r3, r9)
+    r11 = unbox(tuple[int, int, int], r10)
+    return r11
 
 [case testStar2Args]
 from typing import Tuple
@@ -3546,3 +3538,259 @@ L0:
     r2 = PyObject_Vectorcall(r1, 0, 0, 0)
     r3 = box(None, 1)
     return r3
+
+[case testStarArgFastPathTuple]
+from typing import Any, Callable
+def deco(fn: Callable[..., Any]) -> Callable[..., Any]:
+    def wrapper(*args: Any) -> Any:
+        return fn(*args)
+    return wrapper
+
+[out]
+def wrapper_deco_obj.__get__(__mypyc_self__, instance, owner):
+    __mypyc_self__, instance, owner, r0 :: object
+    r1 :: bit
+    r2 :: object
+L0:
+    r0 = load_address _Py_NoneStruct
+    r1 = instance == r0
+    if r1 goto L1 else goto L2 :: bool
+L1:
+    return __mypyc_self__
+L2:
+    r2 = PyMethod_New(__mypyc_self__, instance)
+    return r2
+def wrapper_deco_obj.__call__(__mypyc_self__, args):
+    __mypyc_self__ :: __main__.wrapper_deco_obj
+    args :: tuple
+    r0 :: __main__.deco_env
+    r1, r2 :: object
+L0:
+    r0 = __mypyc_self__.__mypyc_env__
+    r1 = r0.fn
+    r2 = PyObject_CallObject(r1, args)
+    return r2
+def deco(fn):
+    fn :: object
+    r0 :: __main__.deco_env
+    r1 :: bool
+    r2 :: __main__.wrapper_deco_obj
+    r3 :: bool
+    wrapper :: object
+L0:
+    r0 = deco_env()
+    r0.fn = fn; r1 = is_error
+    r2 = wrapper_deco_obj()
+    r2.__mypyc_env__ = r0; r3 = is_error
+    wrapper = r2
+    return wrapper
+
+[case testStarArgFastPathList]
+from typing import Any, Callable, List
+def deco(fn: Callable[..., Any]) -> Callable[[List[Any]], Any]:
+    def wrapper(args: List[Any]) -> Any:
+        return fn(*args)
+    return wrapper
+
+[out]
+def wrapper_deco_obj.__get__(__mypyc_self__, instance, owner):
+    __mypyc_self__, instance, owner, r0 :: object
+    r1 :: bit
+    r2 :: object
+L0:
+    r0 = load_address _Py_NoneStruct
+    r1 = instance == r0
+    if r1 goto L1 else goto L2 :: bool
+L1:
+    return __mypyc_self__
+L2:
+    r2 = PyMethod_New(__mypyc_self__, instance)
+    return r2
+def wrapper_deco_obj.__call__(__mypyc_self__, args):
+    __mypyc_self__ :: __main__.wrapper_deco_obj
+    args :: list
+    r0 :: __main__.deco_env
+    r1 :: object
+    r2 :: tuple
+    r3 :: object
+L0:
+    r0 = __mypyc_self__.__mypyc_env__
+    r1 = r0.fn
+    r2 = PyList_AsTuple(args)
+    r3 = PyObject_CallObject(r1, r2)
+    return r3
+def deco(fn):
+    fn :: object
+    r0 :: __main__.deco_env
+    r1 :: bool
+    r2 :: __main__.wrapper_deco_obj
+    r3 :: bool
+    wrapper :: object
+L0:
+    r0 = deco_env()
+    r0.fn = fn; r1 = is_error
+    r2 = wrapper_deco_obj()
+    r2.__mypyc_env__ = r0; r3 = is_error
+    wrapper = r2
+    return wrapper
+
+[case testStarArgFastPathListWithKwargs]
+from typing import Any, Callable, Dict, List
+def deco(fn: Callable[..., Any]) -> Callable[..., Any]:
+    def wrapper(lst: List[Any], kwargs: Dict[str, Any]) -> Any:
+        return fn(*lst, **kwargs)
+    return wrapper
+
+[out]
+def wrapper_deco_obj.__get__(__mypyc_self__, instance, owner):
+    __mypyc_self__, instance, owner, r0 :: object
+    r1 :: bit
+    r2 :: object
+L0:
+    r0 = load_address _Py_NoneStruct
+    r1 = instance == r0
+    if r1 goto L1 else goto L2 :: bool
+L1:
+    return __mypyc_self__
+L2:
+    r2 = PyMethod_New(__mypyc_self__, instance)
+    return r2
+def wrapper_deco_obj.__call__(__mypyc_self__, lst, kwargs):
+    __mypyc_self__ :: __main__.wrapper_deco_obj
+    lst :: list
+    kwargs :: dict
+    r0 :: __main__.deco_env
+    r1 :: object
+    r2 :: tuple
+    r3 :: dict
+    r4 :: i32
+    r5 :: bit
+    r6 :: object
+L0:
+    r0 = __mypyc_self__.__mypyc_env__
+    r1 = r0.fn
+    r2 = PyList_AsTuple(lst)
+    r3 = PyDict_New()
+    r4 = CPyDict_UpdateInDisplay(r3, kwargs)
+    r5 = r4 >= 0 :: signed
+    r6 = PyObject_Call(r1, r2, r3)
+    return r6
+def deco(fn):
+    fn :: object
+    r0 :: __main__.deco_env
+    r1 :: bool
+    r2 :: __main__.wrapper_deco_obj
+    r3 :: bool
+    wrapper :: object
+L0:
+    r0 = deco_env()
+    r0.fn = fn; r1 = is_error
+    r2 = wrapper_deco_obj()
+    r2.__mypyc_env__ = r0; r3 = is_error
+    wrapper = r2
+    return wrapper
+
+[case testStarArgFastPathSequence]
+from typing import Any, Callable
+def deco(fn: Callable[[Any], Any]) -> Callable[[Any], Any]:
+    def wrapper(args: Any) -> Any:
+        return fn(*args)
+    return wrapper
+
+[out]
+def wrapper_deco_obj.__get__(__mypyc_self__, instance, owner):
+    __mypyc_self__, instance, owner, r0 :: object
+    r1 :: bit
+    r2 :: object
+L0:
+    r0 = load_address _Py_NoneStruct
+    r1 = instance == r0
+    if r1 goto L1 else goto L2 :: bool
+L1:
+    return __mypyc_self__
+L2:
+    r2 = PyMethod_New(__mypyc_self__, instance)
+    return r2
+def wrapper_deco_obj.__call__(__mypyc_self__, args):
+    __mypyc_self__ :: __main__.wrapper_deco_obj
+    args :: object
+    r0 :: __main__.deco_env
+    r1 :: object
+    r2 :: tuple
+    r3 :: object
+L0:
+    r0 = __mypyc_self__.__mypyc_env__
+    r1 = r0.fn
+    r2 = PySequence_Tuple(args)
+    r3 = PyObject_CallObject(r1, r2)
+    return r3
+def deco(fn):
+    fn :: object
+    r0 :: __main__.deco_env
+    r1 :: bool
+    r2 :: __main__.wrapper_deco_obj
+    r3 :: bool
+    wrapper :: object
+L0:
+    r0 = deco_env()
+    r0.fn = fn; r1 = is_error
+    r2 = wrapper_deco_obj()
+    r2.__mypyc_env__ = r0; r3 = is_error
+    wrapper = r2
+    return wrapper
+
+[case testStarArgFastPathSequenceWithKwargs]
+from typing import Any, Callable
+def deco(fn: Callable[[Any], Any]) -> Callable[[Any], Any]:
+    def wrapper(args: Any, **kwargs: Any) -> Any:
+        return fn(*args, **kwargs)
+    return wrapper
+
+[out]
+def wrapper_deco_obj.__get__(__mypyc_self__, instance, owner):
+    __mypyc_self__, instance, owner, r0 :: object
+    r1 :: bit
+    r2 :: object
+L0:
+    r0 = load_address _Py_NoneStruct
+    r1 = instance == r0
+    if r1 goto L1 else goto L2 :: bool
+L1:
+    return __mypyc_self__
+L2:
+    r2 = PyMethod_New(__mypyc_self__, instance)
+    return r2
+def wrapper_deco_obj.__call__(__mypyc_self__, args, kwargs):
+    __mypyc_self__ :: __main__.wrapper_deco_obj
+    args :: object
+    kwargs :: dict
+    r0 :: __main__.deco_env
+    r1 :: object
+    r2 :: tuple
+    r3 :: dict
+    r4 :: i32
+    r5 :: bit
+    r6 :: object
+L0:
+    r0 = __mypyc_self__.__mypyc_env__
+    r1 = r0.fn
+    r2 = PySequence_Tuple(args)
+    r3 = PyDict_New()
+    r4 = CPyDict_UpdateInDisplay(r3, kwargs)
+    r5 = r4 >= 0 :: signed
+    r6 = PyObject_Call(r1, r2, r3)
+    return r6
+def deco(fn):
+    fn :: object
+    r0 :: __main__.deco_env
+    r1 :: bool
+    r2 :: __main__.wrapper_deco_obj
+    r3 :: bool
+    wrapper :: object
+L0:
+    r0 = deco_env()
+    r0.fn = fn; r1 = is_error
+    r2 = wrapper_deco_obj()
+    r2.__mypyc_env__ = r0; r3 = is_error
+    wrapper = r2
+    return wrapper
diff --git a/mypyc/test-data/irbuild-generics.test b/mypyc/test-data/irbuild-generics.test
index d39d47e397a1..03032a7746c0 100644
--- a/mypyc/test-data/irbuild-generics.test
+++ b/mypyc/test-data/irbuild-generics.test
@@ -166,25 +166,18 @@ execute(f, 1)
 def execute(func, args, kwargs):
     func :: object
     args :: tuple
-    kwargs :: dict
-    r0 :: list
-    r1 :: object
-    r2 :: dict
-    r3 :: i32
-    r4 :: bit
-    r5 :: tuple
-    r6 :: object
-    r7 :: int
+    kwargs, r0 :: dict
+    r1 :: i32
+    r2 :: bit
+    r3 :: object
+    r4 :: int
 L0:
-    r0 = PyList_New(0)
-    r1 = CPyList_Extend(r0, args)
-    r2 = PyDict_New()
-    r3 = CPyDict_UpdateInDisplay(r2, kwargs)
-    r4 = r3 >= 0 :: signed
-    r5 = PyList_AsTuple(r0)
-    r6 = PyObject_Call(func, r5, r2)
-    r7 = unbox(int, r6)
-    return r7
+    r0 = PyDict_New()
+    r1 = CPyDict_UpdateInDisplay(r0, kwargs)
+    r2 = r1 >= 0 :: signed
+    r3 = PyObject_Call(func, args, r0)
+    r4 = unbox(int, r3)
+    return r4
 def f(x):
     x :: int
 L0:
@@ -709,14 +702,11 @@ def inner_deco_obj.__call__(__mypyc_self__, args, kwargs):
     can_dictcomp :: dict
     r22, can_iter, r23, can_use_keys, r24, can_use_values :: list
     r25 :: object
-    r26 :: list
-    r27 :: object
-    r28 :: dict
-    r29 :: i32
-    r30 :: bit
-    r31 :: tuple
-    r32 :: object
-    r33 :: int
+    r26 :: dict
+    r27 :: i32
+    r28 :: bit
+    r29 :: object
+    r30 :: int
 L0:
     r0 = __mypyc_self__.__mypyc_env__
     r1 = var_object_size args
@@ -768,15 +758,12 @@ L9:
     r24 = CPyDict_Values(kwargs)
     can_use_values = r24
     r25 = r0.func
-    r26 = PyList_New(0)
-    r27 = CPyList_Extend(r26, args)
-    r28 = PyDict_New()
-    r29 = CPyDict_UpdateInDisplay(r28, kwargs)
-    r30 = r29 >= 0 :: signed
-    r31 = PyList_AsTuple(r26)
-    r32 = PyObject_Call(r25, r31, r28)
-    r33 = unbox(int, r32)
-    return r33
+    r26 = PyDict_New()
+    r27 = CPyDict_UpdateInDisplay(r26, kwargs)
+    r28 = r27 >= 0 :: signed
+    r29 = PyObject_Call(r25, args, r26)
+    r30 = unbox(int, r29)
+    return r30
 def deco(func):
     func :: object
     r0 :: __main__.deco_env