diff --git a/backend/internal/web/handlers_discussion.go b/backend/internal/web/handlers_discussion.go
index e843b5e..07ca9a9 100644
--- a/backend/internal/web/handlers_discussion.go
+++ b/backend/internal/web/handlers_discussion.go
@@ -125,6 +125,18 @@ func DiscussionMessageCreateHandler(deps DiscussionDeps) http.HandlerFunc {
 		message := templates.DiscussionMessageFromRow(row, user.ID)
 		data := templates.DiscussionTabData{Messages: []templates.DiscussionMessageView{message}}
 		markDiscussionRead(r, deps.Queries, tablo, user.ID, data)
+
+		// Send HTTP response before publishing to SSE so the HTMX append (IsOwn=true)
+		// lands in the DOM before the SSE event fires. This prevents the race where SSE
+		// wins, appends IsOwn=false, and messageExists() then blocks the HTMX append.
+		if r.Header.Get("HX-Request") == "true" {
+			w.Header().Set("Content-Type", "text/html; charset=utf-8")
+			_ = templates.DiscussionMessageRow(message).Render(r.Context(), w)
+			if f, ok := w.(http.Flusher); ok {
+				f.Flush()
+			}
+		}
+
 		if deps.Realtime != nil {
 			// SSE recipients are never the author — always render as IsOwn: false.
 			sseMessage := message
@@ -143,12 +155,9 @@ func DiscussionMessageCreateHandler(deps DiscussionDeps) http.HandlerFunc {
 			}
 		}
 
-		if r.Header.Get("HX-Request") == "true" {
-			w.Header().Set("Content-Type", "text/html; charset=utf-8")
-			_ = templates.DiscussionMessageRow(message).Render(r.Context(), w)
-			return
+		if r.Header.Get("HX-Request") != "true" {
+			http.Redirect(w, r, templates.DiscussionURL(tablo.ID), http.StatusSeeOther)
 		}
-		http.Redirect(w, r, templates.DiscussionURL(tablo.ID), http.StatusSeeOther)
 	}
 }