diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -652,6 +652,8 @@
   (`#63169 <https://github.com/llvm/llvm-project/issues/63169>_`)
 - Fix crash when casting an object to an array type.
   (`#63758 <https://github.com/llvm/llvm-project/issues/63758>_`)
+- Fix crash on nested templated class with template function call.
+  (`#61159 <https://github.com/llvm/llvm-project/issues/61159>_`)
 
 Bug Fixes to Compiler Builtins
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
diff --git a/clang/lib/Sema/SemaTemplateInstantiate.cpp b/clang/lib/Sema/SemaTemplateInstantiate.cpp
--- a/clang/lib/Sema/SemaTemplateInstantiate.cpp
+++ b/clang/lib/Sema/SemaTemplateInstantiate.cpp
@@ -258,6 +258,11 @@
                                        /*Final=*/false);
   }
 
+  if (const MemberSpecializationInfo *MSInfo =
+          Rec->getMemberSpecializationInfo())
+    if (MSInfo->getTemplateSpecializationKind() == TSK_ExplicitSpecialization)
+      return Response::Done();
+
   bool IsFriend = Rec->getFriendObjectKind() ||
                   (Rec->getDescribedClassTemplate() &&
                    Rec->getDescribedClassTemplate()->getFriendObjectKind());
diff --git a/clang/test/SemaTemplate/gh61159.cpp b/clang/test/SemaTemplate/gh61159.cpp
new file mode 100644
--- /dev/null
+++ b/clang/test/SemaTemplate/gh61159.cpp
@@ -0,0 +1,21 @@
+// RUN: %clang_cc1 -fsyntax-only -verify -std=c++20 %s
+// expected-no-diagnostics
+
+
+namespace GH61159 {
+template<typename T>
+struct X {
+  struct impl;
+};
+
+
+template <>
+struct X<int>::impl {
+    template<int ct>
+    int f() { return ct; };
+};
+
+void foo() {
+    X<int>::impl{}.f<17>();
+}
+}