diff --git a/samtranslator/model/api/http_api_generator.py b/samtranslator/model/api/http_api_generator.py
index 6f251fef9..ffcbdb023 100644
--- a/samtranslator/model/api/http_api_generator.py
+++ b/samtranslator/model/api/http_api_generator.py
@@ -308,11 +308,16 @@ def _construct_basepath_mappings(self, basepaths, http_api):
                 invalid_regex = r"[^0-9a-zA-Z\/\-\_]+"
                 if re.search(invalid_regex, path) is not None:
                     raise InvalidResourceException(self.logical_id, "Invalid Basepath name provided.")
-                # ignore leading and trailing `/` in the path name
-                m = re.search(r"[a-zA-Z0-9]+[\-\_]?[a-zA-Z0-9]+", path)
-                path = m.string[m.start(0) : m.end(0)]
-                if path is None:
-                    raise InvalidResourceException(self.logical_id, "Invalid Basepath name provided.")
+
+                if path == "/":
+                    path = ""
+                else:
+                    # ignore leading and trailing `/` in the path name
+                    m = re.search(r"[a-zA-Z0-9]+[\-\_]?[a-zA-Z0-9]+", path)
+                    path = m.string[m.start(0) : m.end(0)]
+                    if path is None:
+                        raise InvalidResourceException(self.logical_id, "Invalid Basepath name provided.")
+
                 logical_id = "{}{}{}".format(self.logical_id, re.sub(r"[\-\_]+", "", path), "ApiMapping")
                 basepath_mapping = ApiGatewayV2ApiMapping(logical_id, attributes=self.passthrough_resource_attributes)
                 basepath_mapping.DomainName = ref(self.domain.get("ApiDomainName"))
diff --git a/samtranslator/open_api/open_api.py b/samtranslator/open_api/open_api.py
index 40bea55f9..cadd105e9 100644
--- a/samtranslator/open_api/open_api.py
+++ b/samtranslator/open_api/open_api.py
@@ -334,6 +334,14 @@ def set_path_default_authorizer(self, path, default_authorizer, authorizers, api
             if normalized_method_name != "options":
                 normalized_method_name = self._normalize_method_name(method_name)
                 # It is possible that the method could have two definitions in a Fn::If block.
+                if normalized_method_name not in self.get_path(path):
+                    raise InvalidDocumentException(
+                        [
+                            InvalidTemplateException(
+                                "Could not find {} in {} within DefinitionBody.".format(normalized_method_name, path)
+                            )
+                        ]
+                    )
                 for method_definition in self.get_method_contents(self.get_path(path)[normalized_method_name]):
                     # If no integration given, then we don't need to process this definition (could be AWS::NoValue)
                     if not self.method_definition_has_integration(method_definition):
diff --git a/tests/model/api/test_http_api_generator.py b/tests/model/api/test_http_api_generator.py
index c9656d050..404dd7f41 100644
--- a/tests/model/api/test_http_api_generator.py
+++ b/tests/model/api/test_http_api_generator.py
@@ -237,14 +237,14 @@ def test_basepaths(self):
         self.kwargs["domain"] = {
             "DomainName": "example.com",
             "CertificateArn": "some-url",
-            "BasePath": ["one-1", "two_2", "three"],
+            "BasePath": ["one-1", "two_2", "three", "/"],
             "Route53": {"HostedZoneId": "xyz", "HostedZoneName": "abc", "IpV6": True},
         }
         http_api = HttpApiGenerator(**self.kwargs)._construct_http_api()
         domain, basepath, route = HttpApiGenerator(**self.kwargs)._construct_api_domain(http_api)
         self.assertIsNotNone(domain, None)
         self.assertIsNotNone(basepath, None)
-        self.assertEqual(len(basepath), 3)
+        self.assertEqual(len(basepath), 4)
         self.assertIsNotNone(route, None)
         self.assertEqual(route.HostedZoneName, None)
         self.assertEqual(route.HostedZoneId, "xyz")
diff --git a/tests/translator/input/error_implicit_http_api_auth_any_method.yaml b/tests/translator/input/error_implicit_http_api_auth_any_method.yaml
new file mode 100644
index 000000000..c5b848610
--- /dev/null
+++ b/tests/translator/input/error_implicit_http_api_auth_any_method.yaml
@@ -0,0 +1,24 @@
+Resources:
+  SomeHttpApi:
+    Type: AWS::Serverless::HttpApi
+    Properties:
+      DefinitionBody:
+        paths:
+          "/{domain}":
+            any:
+              responses: {}
+          "/{domain/}{id}":
+            any:
+              responses: {}
+        openapi: 3.0.1
+      Auth:
+        Authorizers:
+          OAuth2Authorizer:
+            AuthorizationScopes:
+            - email
+            JwtConfiguration:
+              audience:
+              - randomnumber
+              issuer: https://some/issuer
+            IdentitySource: "$request.headers.Authorization"
+        DefaultAuthorizer: OAuth2Authorizer
\ No newline at end of file
diff --git a/tests/translator/output/error_implicit_http_api_auth_any_method.json b/tests/translator/output/error_implicit_http_api_auth_any_method.json
new file mode 100644
index 000000000..7064fdf5b
--- /dev/null
+++ b/tests/translator/output/error_implicit_http_api_auth_any_method.json
@@ -0,0 +1,3 @@
+{
+  "errorMessage": "Invalid Serverless Application Specification document. Number of errors found: 1. Structure of the SAM template is invalid. Could not find x-amazon-apigateway-any-method in /{domain} within DefinitionBody."
+}
\ No newline at end of file
diff --git a/tests/translator/test_translator.py b/tests/translator/test_translator.py
index 76f3f291d..db19ce446 100644
--- a/tests/translator/test_translator.py
+++ b/tests/translator/test_translator.py
@@ -658,6 +658,7 @@ def _generate_new_deployment_hash(self, logical_id, dict_to_hash, rest_api_to_sw
         "error_httpapi_mtls_configuration_invalid_field",
         "error_httpapi_mtls_configuration_invalid_type",
         "error_resource_policy_not_dict",
+        "error_implicit_http_api_auth_any_method",
     ],
 )
 @patch("boto3.session.Session.region_name", "ap-southeast-1")