diff --git a/routers/web/repo/compare.go b/routers/web/repo/compare.go
index aebfffb1508..89c36c699cf 100644
--- a/routers/web/repo/compare.go
+++ b/routers/web/repo/compare.go
@@ -148,10 +148,11 @@ func setCsvCompareContext(ctx *context.Context) {
 }
 
 type comparePageInfoType struct {
-	compareInfo      *git_service.CompareInfo
-	nothingToCompare bool
-	allowCreatePull  bool
-	allowEmptyPull   bool
+	compareInfo           *git_service.CompareInfo
+	headRefDownloadSuffix string
+	nothingToCompare      bool
+	allowCreatePull       bool
+	allowEmptyPull        bool
 }
 
 func newComparePageInfo() *comparePageInfoType {
@@ -204,6 +205,18 @@ func (cpi *comparePageInfoType) parseCompareInfo(ctx *context.Context, comparePa
 	}
 
 	headRef, err := common.ResolveRefWithSuffix(ctx, headGitRepo, headRefName, compareReq.HeadOriRefSuffix)
+	if errors.Is(err, util.ErrNotExist) && compareReq.HeadOriRefSuffix == "" {
+		// try to parse "base...head.patch" or "base...head.diff" download suffix
+		var hasDownloadSuffix bool
+		if headRefName, hasDownloadSuffix = strings.CutSuffix(headRefName, ".patch"); hasDownloadSuffix {
+			cpi.headRefDownloadSuffix = ".patch"
+		} else if headRefName, hasDownloadSuffix = strings.CutSuffix(headRefName, ".diff"); hasDownloadSuffix {
+			cpi.headRefDownloadSuffix = ".diff"
+		}
+		if hasDownloadSuffix {
+			headRef, err = common.ResolveRefWithSuffix(ctx, headGitRepo, headRefName, "")
+		}
+	}
 	if err != nil {
 		return err
 	}
@@ -522,6 +535,12 @@ func CompareDiff(ctx *context.Context) {
 		ctx.ServerErrorAuto(err)
 		return
 	}
+
+	if comparePageInfo.headRefDownloadSuffix != "" {
+		downloadCompareDiffOrPatch(ctx, comparePageInfo.compareInfo, comparePageInfo.headRefDownloadSuffix)
+		return
+	}
+
 	ci := comparePageInfo.compareInfo
 	ctx.Data["PageIsViewCode"] = true
 	ctx.Data["PullRequestWorkInProgressPrefixes"] = setting.Repository.PullRequest.WorkInProgressPrefixes
@@ -577,35 +596,12 @@ func CompareDiff(ctx *context.Context) {
 	ctx.HTML(http.StatusOK, tplCompare)
 }
 
-// DownloadCompareDiff render a comparison's raw unified diff
-func DownloadCompareDiff(ctx *context.Context) {
-	downloadCompareDiffOrPatch(ctx, false)
-}
-
-// DownloadComparePatch render a comparison as a git format-patch
-func DownloadComparePatch(ctx *context.Context) {
-	downloadCompareDiffOrPatch(ctx, true)
-}
-
-func downloadCompareDiffOrPatch(ctx *context.Context, patch bool) {
-	// The route captures `basehead` separately so the `.diff`/`.patch` suffix is
-	// stripped from the catch-all `*` param parseCompareInfo would otherwise read.
-	cpi := newComparePageInfo()
-	if err := cpi.parseCompareInfo(ctx, ctx.PathParam("basehead")); err != nil {
-		if errors.Is(err, util.ErrNotExist) || errors.Is(err, util.ErrInvalidArgument) {
-			ctx.NotFound()
-		} else {
-			ctx.ServerErrorAuto(err)
-		}
-		return
-	}
-	ci := cpi.compareInfo
-
+func downloadCompareDiffOrPatch(ctx *context.Context, ci *git_service.CompareInfo, downloadSuffix string) {
 	ctx.Resp.Header().Set("Content-Type", "text/plain; charset=utf-8")
 	compareArg := ci.BaseCommitID + ci.CompareSeparator + ci.HeadCommitID
 
 	var err error
-	if patch {
+	if downloadSuffix == ".patch" {
 		err = ci.HeadGitRepo.GetPatch(ctx, compareArg, ctx.Resp)
 	} else {
 		err = ci.HeadGitRepo.GetDiff(ctx, compareArg, ctx.Resp)
diff --git a/routers/web/web.go b/routers/web/web.go
index f9c5b68c68e..bf4697ac2a3 100644
--- a/routers/web/web.go
+++ b/routers/web/web.go
@@ -1280,12 +1280,8 @@ func registerWebRoutes(m *web.Router, webAuth *AuthMiddleware) {
 			m.Get("/commit/*", context.RepoRefByType(git.RefTypeCommit), repo.TreeViewNodes)
 		})
 		m.Get("/compare", repo.MustBeNotEmpty, repo.SetEditorconfigIfExists, repo.SetDiffViewStyle, repo.SetWhitespaceBehavior, repo.CompareDiff)
-		m.PathGroup("/compare/*", func(g *web.RouterPathGroup) {
-			g.MatchPath("GET", "/<basehead:*>.diff", repo.MustBeNotEmpty, repo.DownloadCompareDiff)
-			g.MatchPath("GET", "/<basehead:*>.patch", repo.MustBeNotEmpty, repo.DownloadComparePatch)
-			g.MatchPath("GET", "/<*:*>", repo.MustBeNotEmpty, repo.SetEditorconfigIfExists, repo.SetDiffViewStyle, repo.SetWhitespaceBehavior, repo.CompareDiff)
-			g.MatchPath("POST", "/<*:*>", repo.MustBeNotEmpty, repo.SetEditorconfigIfExists, reqSignIn, context.RepoMustNotBeArchived(), reqUnitPullsReader, repo.MustAllowPulls, web.Bind[*forms.CreateIssueForm](), repo.SetWhitespaceBehavior, repo.CompareAndPullRequestPost)
-		})
+		m.Get("/compare/*", repo.MustBeNotEmpty, repo.SetEditorconfigIfExists, repo.SetDiffViewStyle, repo.SetWhitespaceBehavior, repo.CompareDiff)
+		m.Post("/compare/*", repo.MustBeNotEmpty, repo.SetEditorconfigIfExists, reqSignIn, context.RepoMustNotBeArchived(), reqUnitPullsReader, repo.MustAllowPulls, web.Bind[*forms.CreateIssueForm](), repo.SetWhitespaceBehavior, repo.CompareAndPullRequestPost)
 		m.Get("/pulls/new/*", repo.PullsNewRedirect)
 	}, optSignIn, context.RepoAssignment, reqUnitCodeReader)
 	// end "/{username}/{reponame}": repo code: find, compare, list
diff --git a/tests/integration/compare_test.go b/tests/integration/compare_test.go
index a42a3758e70..4e498842f39 100644
--- a/tests/integration/compare_test.go
+++ b/tests/integration/compare_test.go
@@ -236,6 +236,22 @@ func TestCompare(t *testing.T) {
 			assert.Contains(t, resp.Body.String(), "diff --git ")
 		})
 
+		t.Run("BranchNamesConflictingWithOutputSuffix", func(t *testing.T) {
+			defer tests.PrintCurrentTest(t)()
+
+			repo := unittest.AssertExistsAndLoadBean(t, &repo_model.Repository{ID: 31})
+			for _, branch := range []string{"diff", "patch", "feature.diff", "feature.patch"} {
+				_, _, err := gitcmd.NewCommand("branch").AddDynamicArguments(branch, "add-csv").WithRepo(repo).RunStdString(t.Context())
+				require.NoError(t, err)
+			}
+
+			for _, branch := range []string{"diff", "patch", "feature.diff", "feature.patch"} {
+				req := NewRequest(t, "GET", "/user2/repo20/compare/master..."+branch)
+				resp := session.MakeRequest(t, req, http.StatusOK)
+				assert.True(t, test.IsNormalPageCompleted(resp.Body.String()), "branch %q should render the compare page", branch)
+			}
+		})
+
 		t.Run("InvalidBaseRef", func(t *testing.T) {
 			defer tests.PrintCurrentTest(t)()