diff --git a/packages/runtime/src/enhancements/default-auth.ts b/packages/runtime/src/enhancements/default-auth.ts
index 78294f28b..56e43ab29 100644
--- a/packages/runtime/src/enhancements/default-auth.ts
+++ b/packages/runtime/src/enhancements/default-auth.ts
@@ -92,6 +92,11 @@ class DefaultAuthHandler extends DefaultPrismaProxyHandler {
     }
 
     private setAuthDefaultValue(fieldInfo: FieldInfo, model: string, data: any, authDefaultValue: unknown) {
+        if (fieldInfo.isForeignKey && fieldInfo.relationField && fieldInfo.relationField in data) {
+            // if the field is a fk, and the relation field is already set, we should not override it
+            return;
+        }
+
         if (fieldInfo.isForeignKey && !isUnsafeMutate(model, data, this.options.modelMeta)) {
             // if the field is a fk, and the create payload is not unsafe, we need to translate
             // the fk field setting to a `connect` of the corresponding relation field
diff --git a/tests/integration/tests/enhancements/with-policy/auth.test.ts b/tests/integration/tests/enhancements/with-policy/auth.test.ts
index 9079da045..0cac82e8a 100644
--- a/tests/integration/tests/enhancements/with-policy/auth.test.ts
+++ b/tests/integration/tests/enhancements/with-policy/auth.test.ts
@@ -417,10 +417,11 @@ describe('auth() runtime test', () => {
     });
 
     it('Default auth() with foreign key', async () => {
-        const { enhance, modelMeta } = await loadSchema(
+        const { enhance, prisma } = await loadSchema(
             `
         model User {
             id String @id
+            email String @unique
             posts Post[]
 
             @@allow('all', true)
@@ -438,9 +439,23 @@ describe('auth() runtime test', () => {
         `
         );
 
+        await prisma.user.create({ data: { id: 'userId-1', email: 'user1@abc.com' } });
+        await prisma.user.create({ data: { id: 'userId-2', email: 'user2@abc.com' } });
+
         const db = enhance({ id: 'userId-1' });
-        await expect(db.user.create({ data: { id: 'userId-1' } })).toResolveTruthy();
-        await expect(db.post.create({ data: { title: 'abc' } })).resolves.toMatchObject({ authorId: 'userId-1' });
+
+        // default auth effective
+        await expect(db.post.create({ data: { title: 'post1' } })).resolves.toMatchObject({ authorId: 'userId-1' });
+
+        // default auth ineffective due to explicit connect
+        await expect(
+            db.post.create({ data: { title: 'post2', author: { connect: { email: 'user1@abc.com' } } } })
+        ).resolves.toMatchObject({ authorId: 'userId-1' });
+
+        // default auth ineffective due to explicit connect
+        await expect(
+            db.post.create({ data: { title: 'post3', author: { connect: { email: 'user2@abc.com' } } } })
+        ).resolves.toMatchObject({ authorId: 'userId-2' });
     });
 
     it('Default auth() with nested user context value', async () => {