diff --git a/components/organization/hackathons/rewards/types.ts b/components/organization/hackathons/rewards/types.ts
index 0633aaaf..788d1adf 100644
--- a/components/organization/hackathons/rewards/types.ts
+++ b/components/organization/hackathons/rewards/types.ts
@@ -1,5 +1,12 @@
 export interface Submission {
   id: string;
+  /**
+   * The actual HackathonSubmission row ID, distinct from `id` which the
+   * rewards data mapper sets to the participant ID. Required for
+   * matching submissions against backend payloads (judging results,
+   * track winners) that key by submissionId.
+   */
+  submissionId?: string;
   name: string;
   projectName: string;
   avatar?: string;
diff --git a/hooks/use-hackathon-rewards.ts b/hooks/use-hackathon-rewards.ts
index 2b4a8fe4..ec4240cd 100644
--- a/hooks/use-hackathon-rewards.ts
+++ b/hooks/use-hackathon-rewards.ts
@@ -472,7 +472,14 @@ export const useHackathonRewards = (
         const byId = new Map(fetched.map(tw => [tw.submissionId, tw]));
         setSubmissions(prev =>
           prev.map(sub => {
-            const tw = byId.get(sub.id);
+            // Match against the real submission row ID (now threaded
+            // through by the mapper). Fall back to `sub.id` for any
+            // mapper output that predates the `submissionId` field —
+            // older rows would have `id === submissionId` when
+            // participant data was missing.
+            const tw =
+              (sub.submissionId && byId.get(sub.submissionId)) ||
+              byId.get(sub.id);
             if (!tw) return sub;
             return {
               ...sub,
diff --git a/lib/utils/rewards-data-mapper.ts b/lib/utils/rewards-data-mapper.ts
index a423640e..67137675 100644
--- a/lib/utils/rewards-data-mapper.ts
+++ b/lib/utils/rewards-data-mapper.ts
@@ -63,6 +63,12 @@ export const mapJudgingSubmissionToRewardSubmission = (
 
   return {
     id: participant.id || sub.id || '',
+    // The real submission row ID, used by backend payloads (judging
+    // results, track winners) that key by submissionId. The mapper's
+    // `id` field stays on the participant ID for compatibility with
+    // existing rank-assignment and display code that already keys off
+    // it.
+    submissionId: submissionData.id || sub.id || sub.submissionId || '',
     participantId: participant.id || sub.id || '',
     name,
     projectName: submissionData.projectName || '',