diff --git a/app/services/ci/create_pipeline_service.rb b/app/services/ci/create_pipeline_service.rb
index 3b3d9239086f135317cf3b68d4b352fdd8c1f782..ad27f320853bf39c0c9ef26963bf18537b0d979e 100644
--- a/app/services/ci/create_pipeline_service.rb
+++ b/app/services/ci/create_pipeline_service.rb
@@ -65,7 +65,7 @@ module Ci
       project.pipelines
         .where(ref: pipeline.ref)
         .where.not(id: pipeline.id)
-        .where.not(sha: project.repository.sha_from_ref(pipeline.ref))
+        .where.not(sha: project.commit(pipeline.ref).try(:id))
         .created_or_pending
     end
 
diff --git a/changelogs/unreleased/ci-pipeline-commit-lookup.yml b/changelogs/unreleased/ci-pipeline-commit-lookup.yml
new file mode 100644
index 0000000000000000000000000000000000000000..b2a1e4c21634bca8e02c63a7df58ca6fef8e076e
--- /dev/null
+++ b/changelogs/unreleased/ci-pipeline-commit-lookup.yml
@@ -0,0 +1,5 @@
+---
+title: Use porcelain commit lookup method on CI::CreatePipelineService
+merge_request: 17911
+author:
+type: fixed
diff --git a/lib/gitlab/git/repository.rb b/lib/gitlab/git/repository.rb
index 208710b0935cd953359b539a47623e5d802a0bf1..c15c128507d3c661771148e58006d427feb59bb3 100644
--- a/lib/gitlab/git/repository.rb
+++ b/lib/gitlab/git/repository.rb
@@ -516,10 +516,6 @@ module Gitlab
         end
       end
 
-      def sha_from_ref(ref)
-        rev_parse_target(ref).oid
-      end
-
       # Return the object that +revspec+ points to.  If +revspec+ is an
       # annotated tag, then return the tag's target instead.
       def rev_parse_target(revspec)
@@ -2409,6 +2405,10 @@ module Gitlab
       def rev_list_param(spec)
         spec == :all ? ['--all'] : spec
       end
+
+      def sha_from_ref(ref)
+        rev_parse_target(ref).oid
+      end
     end
   end
 end