diff --git a/routers/web/repo/issue_comment.go b/routers/web/repo/issue_comment.go
index df908277546..419dce03f30 100644
--- a/routers/web/repo/issue_comment.go
+++ b/routers/web/repo/issue_comment.go
@@ -17,7 +17,6 @@ import (
 	"gitea.dev/modules/git"
 	"gitea.dev/modules/log"
 	"gitea.dev/modules/markup/markdown"
-	repo_module "gitea.dev/modules/repository"
 	"gitea.dev/modules/setting"
 	api "gitea.dev/modules/structs"
 	"gitea.dev/modules/util"
@@ -137,21 +136,9 @@ func NewComment(ctx *context.Context) {
 					return
 				}
 
-				err = pull.LoadIssue(ctx)
-				if err != nil {
-					ctx.ServerError("load the issue of pull request error", err)
-					return
-				}
-
 				if prHeadCommitID != headBranchCommitID {
-					// force push to base repo
-					err := git.PushManaged(ctx, pull.HeadRepo, pull.BaseRepo, git.PushOptions{
-						Branch: pull.HeadBranch + ":" + prHeadRef,
-						Force:  true,
-						Env:    repo_module.InternalPushingEnvironment(pull.Issue.Poster, pull.BaseRepo),
-					})
-					if err != nil {
-						ctx.ServerError("force push error", err)
+					if err := pull_service.PushToBaseRepo(ctx, pull); err != nil {
+						ctx.ServerError("PushToBaseRepo", err)
 						return
 					}
 				}
diff --git a/services/pull/pull.go b/services/pull/pull.go
index 1cf18f1acff..46550087ff8 100644
--- a/services/pull/pull.go
+++ b/services/pull/pull.go
@@ -556,11 +556,10 @@ func checkIfPRContentChanged(ctx context.Context, pr *issues_model.PullRequest,
 	return false, mergeBase, nil
 }
 
-// PushToBaseRepo pushes commits from branches of head repository to
-// corresponding branches of base repository.
-// FIXME: Only push branches that are actually updates?
+// PushToBaseRepo fetches the head branch commit into the base repository and points the PR head ref at it.
+// FIXME: Only update refs that actually changed?
 func PushToBaseRepo(ctx context.Context, pr *issues_model.PullRequest) error {
-	log.Trace("PushToBaseRepo[%d]: pushing commits to base repo '%s'", pr.BaseRepoID, pr.GetGitHeadRefName())
+	log.Trace("PushToBaseRepo[%d]: updating base repo ref '%s'", pr.BaseRepoID, pr.GetGitHeadRefName())
 
 	if err := pr.LoadHeadRepo(ctx); err != nil {
 		return err
@@ -571,23 +570,17 @@ func PushToBaseRepo(ctx context.Context, pr *issues_model.PullRequest) error {
 	if err := pr.LoadIssue(ctx); err != nil {
 		return err
 	}
-	if err := pr.Issue.LoadPoster(ctx); err != nil {
+
+	headCommitID, err := git.GetFullCommitID(ctx, pr.HeadRepo, git.BranchPrefix+pr.HeadBranch)
+	if err != nil {
 		return err
 	}
-
-	baseRepoHeadRefName := pr.GetGitHeadRefName()
-	if err := git.PushManaged(ctx, pr.HeadRepo, pr.BaseRepo, git.PushOptions{
-		Branch: git.BranchPrefix + pr.HeadBranch + ":" + baseRepoHeadRefName,
-		Force:  true,
-		// Use InternalPushingEnvironment here because we know that pre-receive and post-receive do not run on a refs/pulls/...
-		Env: repo_module.InternalPushingEnvironment(pr.Issue.Poster, pr.BaseRepo),
-	}); err != nil {
-		// Since we use internal force-push, there should be no git error.
-		// If any error happens, it must be an internal error (e.g.: broken git hooks) but not user error.
-		return fmt.Errorf("unable to push from head branch %s:%s to base repo %s:%s, err: %w",
-			pr.HeadRepo.FullName(), pr.HeadBranch, pr.BaseRepo.FullName(), baseRepoHeadRefName, err)
+	// fetch, not push: pushing objects FetchRemoteCommit already fetched races background repacks
+	if err := git.FetchRemoteCommit(ctx, pr.BaseRepo, pr.HeadRepo, headCommitID); err != nil {
+		return fmt.Errorf("unable to fetch head branch %s:%s into base repo %s, err: %w",
+			pr.HeadRepo.FullName(), pr.HeadBranch, pr.BaseRepo.FullName(), err)
 	}
-	return nil
+	return git.UpdateRef(ctx, pr.BaseRepo, pr.GetGitHeadRefName(), headCommitID)
 }
 
 // UpdatePullsRefs update all the PRs head file pointers like /refs/pull/1/head so that it will be dependent by other operations