diff --git a/apps/web/locales/cs.json b/apps/web/locales/cs.json
index f3188c6e0..beda56ed6 100644
--- a/apps/web/locales/cs.json
+++ b/apps/web/locales/cs.json
@@ -134,6 +134,7 @@
     "tieDeltaNote": "(stejné skóre při aktuálních vahách)",
     "tie1v1Badge": "Remíza 1v1",
     "versusAutoVerdictTie": "Automatický verdikt: oba modely mají stejné celkové skóre ({score}); rozhodněte podle ceny a parametrů, které potřebujete.",
+    "versusAutoVerdictNoScore": "Automatický verdikt: ani jeden model zatím nemá hodnocení; rozhodněte podle ceny a parametrů, které potřebujete.",
     "versusVerdictWeights": "(Váhy: {weights}.)",
     "compareMetaTitleWithNames": "Porovnání {names} - Hodnocení a 10 skupin parametrů | Rate.vn",
     "compareMetaTitleWithNamesShort": "{names} | Rate.vn",
diff --git a/apps/web/locales/en.json b/apps/web/locales/en.json
index e290e6683..270b8366f 100644
--- a/apps/web/locales/en.json
+++ b/apps/web/locales/en.json
@@ -134,6 +134,7 @@
     "tieDeltaNote": "(same score with the current weights)",
     "tie1v1Badge": "1v1 Tie",
     "versusAutoVerdictTie": "Automatic verdict: the two models are level on overall score ({score}); choose on price and the specs you need.",
+    "versusAutoVerdictNoScore": "Automatic verdict: neither model has a rating yet; choose on price and the specs you need.",
     "versusVerdictWeights": "(Weights: {weights}.)",
     "compareMetaTitleWithNames": "Compare {names} - Ratings and 10 spec groups | Rate.vn",
     "compareMetaTitleWithNamesShort": "{names} | Rate.vn",
diff --git a/apps/web/locales/vi.json b/apps/web/locales/vi.json
index fec693473..0eec6824f 100644
--- a/apps/web/locales/vi.json
+++ b/apps/web/locales/vi.json
@@ -134,6 +134,7 @@
     "tieDeltaNote": "(cùng điểm theo trọng số hiện tại)",
     "tie1v1Badge": "Ngang điểm 1v1",
     "versusAutoVerdictTie": "Kết luận tự động: hai mẫu ngang điểm tổng hợp ({score}), chọn theo giá và thông số bạn cần.",
+    "versusAutoVerdictNoScore": "Kết luận tự động: cả hai mẫu chưa có đánh giá, chọn theo giá và thông số bạn cần.",
     "versusVerdictWeights": "(Theo trọng số: {weights}.)",
     "compareMetaTitleWithNames": "So sánh {names} - Điểm đánh giá và 10 nhóm thông số | Rate.vn",
     "compareMetaTitleWithNamesShort": "{names} | Rate.vn",
diff --git a/apps/web/src/app/api/v1/rate/__tests__/spec-scope.test.ts b/apps/web/src/app/api/v1/rate/__tests__/spec-scope.test.ts
index 84993d111..1a05d83ef 100644
--- a/apps/web/src/app/api/v1/rate/__tests__/spec-scope.test.ts
+++ b/apps/web/src/app/api/v1/rate/__tests__/spec-scope.test.ts
@@ -883,7 +883,20 @@ async function testSpecMatchesBodies() {
     get(`/api/v1/rate/versus?pair=${PHONE.slug}-vs-${PHONE_2.slug}`)
   );
   assert.equal(vs.status, 200);
-  expectPaths('/api/v1/rate/versus', await vs.json(), [
+  const vsBody = await vs.json();
+  // The tie and the winner read the /10 scores as shown, at one decimal
+  // (#1545): a tie only when they are equal, else the higher one wins.
+  const vsA10 = vsBody.product_a.custom_weighted_score_10;
+  const vsB10 = vsBody.product_b.custom_weighted_score_10;
+  assert.equal(vsBody.is_tie, vsA10 === vsB10);
+  if (!vsBody.is_tie) {
+    assert.equal(vsBody.overall_winner.side, vsA10 > vsB10 ? 'A' : 'B');
+    assert.equal(
+      vsBody.overall_winner.margin_10,
+      Number(Math.abs(vsA10 - vsB10).toFixed(1))
+    );
+  }
+  expectPaths('/api/v1/rate/versus', vsBody, [
     'is_tie',
     'versus_pair',
     ...under('deal_radar.productA', radar),
diff --git a/apps/web/src/app/api/v1/rate/versus/route.ts b/apps/web/src/app/api/v1/rate/versus/route.ts
index 76aeba948..089388a7c 100644
--- a/apps/web/src/app/api/v1/rate/versus/route.ts
+++ b/apps/web/src/app/api/v1/rate/versus/route.ts
@@ -7,6 +7,7 @@ import {
   getMasterProductOffersBatch,
 } from '@/server/rate';
 import { radarExportFields } from '@/lib/deal-radar';
+import { versusApiWinner } from '@/lib/versus-verdict';
 import {
   comparePositiveMinPrices,
   scoreMasterProductForLeaderboard,
@@ -305,18 +306,16 @@ export async function GET(req: NextRequest) {
       scoreB.minPrice
     );
 
-    const winnerSide: 'A' | 'B' =
-      customScoreA5 > customScoreB5
-        ? 'A'
-        : customScoreB5 > customScoreA5
-          ? 'B'
-          : scoreA.combinedScore5 > scoreB.combinedScore5
-            ? 'A'
-            : scoreB.combinedScore5 > scoreA.combinedScore5
-              ? 'B'
-              : priceSide === 'B'
-                ? 'B'
-                : 'A';
+    // The winner and the tie read the scores as the response shows them, at
+    // one decimal; the composite and then the price only break a tie
+    // (DOS/Rate#1545, D3).
+    const { tie: isTie, side: winnerSide } = versusApiWinner(
+      customScoreA10,
+      customScoreB10,
+      scoreA.combinedScore5,
+      scoreB.combinedScore5,
+      priceSide
+    );
 
     const winnerScore = winnerSide === 'A' ? scoreA : scoreB;
     const winnerCustom10 = winnerSide === 'A' ? customScoreA10 : customScoreB10;
@@ -399,11 +398,9 @@ export async function GET(req: NextRequest) {
           productA: radarSignalA,
           productB: radarSignalB,
         },
-        // Level at two decimals: overall_winner is then only the tie-break
-        // (DOS/Rate#1209).
-        is_tie:
-          customScoreA5.toFixed(2) === customScoreB5.toFixed(2) &&
-          scoreA.combinedScore5.toFixed(2) === scoreB.combinedScore5.toFixed(2),
+        // Level at the shown precision: overall_winner is then only the
+        // tie-break (DOS/Rate#1209, DOS/Rate#1545).
+        is_tie: isTie,
         overall_winner: {
           side: winnerSide,
           slug: winnerScore.slug,
diff --git a/apps/web/src/components/compare/VersusInteractiveScoreboard.tsx b/apps/web/src/components/compare/VersusInteractiveScoreboard.tsx
index d56406d4c..4680e6fa4 100644
--- a/apps/web/src/components/compare/VersusInteractiveScoreboard.tsx
+++ b/apps/web/src/components/compare/VersusInteractiveScoreboard.tsx
@@ -187,6 +187,10 @@ export default function VersusInteractiveScoreboard({
   const scoreA = swapped ? secondScore : firstScore;
   const scoreB = swapped ? firstScore : secondScore;
   const t = useTranslations('compare');
+  const tStars = useTranslations('starRating');
+  // A side with no score reads like its stars, not "0.0" (DOS/Rate#1545).
+  const summaryScore = (score: number): string =>
+    score > 0 ? formatDecimal(score, locale, 1) : tStars('empty');
   const locale = useLocale();
   const useCaseLabelId = useId();
   const slidersPanelId = useId();
@@ -479,9 +483,11 @@ export default function VersusInteractiveScoreboard({
         aria-live="polite"
       >
         {/* Narrows the values to each key's own placeholders. */}
-        {verdict.key === 'versusAutoVerdictTie'
-          ? t(verdict.key, verdict.values)
-          : t(verdict.key, verdict.values)}
+        {verdict.key === 'versusAutoVerdictNoScore'
+          ? t(verdict.key)
+          : verdict.key === 'versusAutoVerdictTie'
+            ? t(verdict.key, verdict.values)
+            : t(verdict.key, verdict.values)}
         {verdict.weightsLabel &&
           ` ${t('versusVerdictWeights', { weights: verdict.weightsLabel })}`}
       </p>
@@ -650,8 +656,8 @@ export default function VersusInteractiveScoreboard({
             )}
           </div>
           <div className="rate-tabular small text-warning fw-bold">
-            {scoreA.brand}: {formatDecimal(weightedResult.finalA, locale, 1)} •{' '}
-            {scoreB.brand}: {formatDecimal(weightedResult.finalB, locale, 1)}
+            {scoreA.brand}: {summaryScore(weightedResult.finalA)} •{' '}
+            {scoreB.brand}: {summaryScore(weightedResult.finalB)}
           </div>
         </div>
 
diff --git a/apps/web/src/lib/__tests__/locale-format.test.ts b/apps/web/src/lib/__tests__/locale-format.test.ts
index e182d50da..6b53579de 100644
--- a/apps/web/src/lib/__tests__/locale-format.test.ts
+++ b/apps/web/src/lib/__tests__/locale-format.test.ts
@@ -7,7 +7,7 @@ import { radarExplanation } from '../product-detail-copy';
 import { weightExplanationCopy } from '../review-display';
 import { fitTitle } from '../seo';
 import { localizeSpecValue } from '../spec-localizer';
-import { versusVerdictCopy } from '../versus-verdict';
+import { versusApiWinner, versusVerdictCopy } from '../versus-verdict';
 import {
   NBSP,
   collapseWhitespace,
@@ -313,6 +313,30 @@ assert.deepEqual(
   versusVerdictCopy({ ...versusInput, tie: true }, 'cs').values,
   { score: '4,9' }
 );
+// Neither model has a score: no "0.0" tie (DOS/Rate#1545).
+assert.equal(
+  versusVerdictCopy({ ...versusInput, tie: true, score: 0 }).key,
+  'versusAutoVerdictNoScore'
+);
+
+// The 1v1 API decides on the /10 scores at one decimal; the composite and
+// then the lower price only break a tie (DOS/Rate#1545).
+assert.deepEqual(versusApiWinner(8.9, 8.7, 4.0, 4.9, 'B'), {
+  tie: false,
+  side: 'A',
+});
+assert.deepEqual(versusApiWinner(9.04, 8.96, 4.0, 4.9, 'A'), {
+  tie: true,
+  side: 'B',
+});
+assert.deepEqual(versusApiWinner(9.0, 9.0, 4.5, 4.5, 'B'), {
+  tie: true,
+  side: 'B',
+});
+assert.deepEqual(versusApiWinner(9.0, 9.0, 4.5, 4.5, 'equal'), {
+  tie: true,
+  side: 'A',
+});
 
 // cs.json: a placeholder before % or ₫ is joined by one U+00A0, and no
 // rating scale is written `/ 5.0`.
diff --git a/apps/web/src/lib/versus-verdict.ts b/apps/web/src/lib/versus-verdict.ts
index 1eac07024..8ce1659d3 100644
--- a/apps/web/src/lib/versus-verdict.ts
+++ b/apps/web/src/lib/versus-verdict.ts
@@ -10,6 +10,32 @@ export function isVersusScoreTie(scoreA: number, scoreB: number): boolean {
   return scoreA.toFixed(1) === scoreB.toFixed(1);
 }
 
+/**
+ * The 1v1 API's winner and tie (DOS/Rate#1545): the persona scores on 10, at
+ * one decimal as the response shows them, decide; on a tie the composite,
+ * then the lower price, then side A only pick `overall_winner`.
+ */
+export function versusApiWinner(
+  score10A: number,
+  score10B: number,
+  combined5A: number,
+  combined5B: number,
+  lowerPriceSide: string | null | undefined
+): { tie: boolean; side: 'A' | 'B' } {
+  const a = Number.isFinite(score10A) ? Number(score10A.toFixed(1)) : 0;
+  const b = Number.isFinite(score10B) ? Number(score10B.toFixed(1)) : 0;
+  if (a !== b) return { tie: false, side: a > b ? 'A' : 'B' };
+  const side: 'A' | 'B' =
+    combined5A > combined5B
+      ? 'A'
+      : combined5B > combined5A
+        ? 'B'
+        : lowerPriceSide === 'B'
+          ? 'B'
+          : 'A';
+  return { tie: true, side };
+}
+
 export interface VersusVerdictInput {
   tie: boolean;
   /** The leader's score under the weights in use (either side on a tie). */
@@ -21,6 +47,11 @@ export interface VersusVerdictInput {
 }
 
 export type VersusVerdictCopy =
+  | {
+      key: 'versusAutoVerdictNoScore';
+      values: Record<string, never>;
+      weightsLabel: string | null;
+    }
   | {
       key: 'versusAutoVerdictTie';
       values: { score: string };
@@ -41,6 +72,15 @@ export function versusVerdictCopy(
   input: VersusVerdictInput,
   locale?: string | null
 ): VersusVerdictCopy {
+  // Level because neither model has a score yet: say so, as the stars do,
+  // instead of a "0.0" tie (DOS/Rate#1545).
+  if (input.tie && !(input.score > 0)) {
+    return {
+      key: 'versusAutoVerdictNoScore',
+      values: {},
+      weightsLabel: input.weightsLabel,
+    };
+  }
   const score = formatDecimal(input.score, locale, 1);
   if (input.tie) {
     return {
diff --git a/apps/web/src/server/rate/openapi.ts b/apps/web/src/server/rate/openapi.ts
index 457893dcc..c6e68107a 100644
--- a/apps/web/src/server/rate/openapi.ts
+++ b/apps/web/src/server/rate/openapi.ts
@@ -627,7 +627,7 @@ function buildBaseRateOpenApiSpec(
           summary:
             'Get programmatic 1v1 Head-to-Head JReviews verdict, 5-criteria scoreboard & price delta',
           description:
-            'Evaluates two same-category master products (`?pair=<slugA>-vs-<slugB>` or `?slugA=...&slugB=...`) with optional persona/custom 5-criteria weights (`persona`, `w_screen`, `w_performance`, `w_camera`, `w_battery`, `w_value`) and returns the overall winner (with `is_tie` true when both scores are level at two decimals; `overall_winner` is then only the price or side-A tie-break), per-criterion head-to-head breakdown, price delta, Deal Radar signals (`deal_radar`), and 10-group specs.',
+            'Evaluates two same-category master products (`?pair=<slugA>-vs-<slugB>` or `?slugA=...&slugB=...`) with optional persona/custom 5-criteria weights (`persona`, `w_screen`, `w_performance`, `w_camera`, `w_battery`, `w_value`) and returns the overall winner (with `is_tie` true when both `custom_weighted_score_10` values are equal at one decimal; `overall_winner` is then only the tie-break: the combined score, then the lower price, then side A), per-criterion head-to-head breakdown, price delta, Deal Radar signals (`deal_radar`), and 10-group specs.',
           tags: ['Comparison & Watchlist'],
           parameters: [
             {