diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 833428e3321db..07bbb846b466b 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -20855,6 +20855,8 @@ namespace ts {
                     return isAccessExpression(target) &&
                         getAccessedPropertyName(<AccessExpression>source) === getAccessedPropertyName(target) &&
                         isMatchingReference((<AccessExpression>source).expression, target.expression);
+                case SyntaxKind.BinaryExpression:
+                    return (isBinaryExpression(source) && source.operatorToken.kind === SyntaxKind.CommaToken && isMatchingReference(source.right, target));
             }
             return false;
         }
diff --git a/tests/baselines/reference/narrowCommaOperatorNestedWithinLHS.js b/tests/baselines/reference/narrowCommaOperatorNestedWithinLHS.js
new file mode 100644
index 0000000000000..a3137b050c22b
--- /dev/null
+++ b/tests/baselines/reference/narrowCommaOperatorNestedWithinLHS.js
@@ -0,0 +1,32 @@
+//// [narrowCommaOperatorNestedWithinLHS.ts]
+const otherValue = () => true;
+const value: { inner: number | string } = null as any;
+
+function isNumber(obj: any): obj is number {
+    return true; // method implementation irrelevant
+}
+
+if (typeof (otherValue(), value).inner === 'number') {
+    const a = value.inner; // number
+    const b: number = (otherValue(), value).inner; // string | number , but should be number
+}
+
+if (isNumber((otherValue(), value).inner)) {
+    const a = value.inner; // number
+    const b: number = (otherValue(), value).inner; // string | number , but should be number
+}
+
+//// [narrowCommaOperatorNestedWithinLHS.js]
+var otherValue = function () { return true; };
+var value = null;
+function isNumber(obj) {
+    return true; // method implementation irrelevant
+}
+if (typeof (otherValue(), value).inner === 'number') {
+    var a = value.inner; // number
+    var b = (otherValue(), value).inner; // string | number , but should be number
+}
+if (isNumber((otherValue(), value).inner)) {
+    var a = value.inner; // number
+    var b = (otherValue(), value).inner; // string | number , but should be number
+}
diff --git a/tests/baselines/reference/narrowCommaOperatorNestedWithinLHS.symbols b/tests/baselines/reference/narrowCommaOperatorNestedWithinLHS.symbols
new file mode 100644
index 0000000000000..c1f0a7b940188
--- /dev/null
+++ b/tests/baselines/reference/narrowCommaOperatorNestedWithinLHS.symbols
@@ -0,0 +1,56 @@
+=== tests/cases/compiler/narrowCommaOperatorNestedWithinLHS.ts ===
+const otherValue = () => true;
+>otherValue : Symbol(otherValue, Decl(narrowCommaOperatorNestedWithinLHS.ts, 0, 5))
+
+const value: { inner: number | string } = null as any;
+>value : Symbol(value, Decl(narrowCommaOperatorNestedWithinLHS.ts, 1, 5))
+>inner : Symbol(inner, Decl(narrowCommaOperatorNestedWithinLHS.ts, 1, 14))
+
+function isNumber(obj: any): obj is number {
+>isNumber : Symbol(isNumber, Decl(narrowCommaOperatorNestedWithinLHS.ts, 1, 54))
+>obj : Symbol(obj, Decl(narrowCommaOperatorNestedWithinLHS.ts, 3, 18))
+>obj : Symbol(obj, Decl(narrowCommaOperatorNestedWithinLHS.ts, 3, 18))
+
+    return true; // method implementation irrelevant
+}
+
+if (typeof (otherValue(), value).inner === 'number') {
+>(otherValue(), value).inner : Symbol(inner, Decl(narrowCommaOperatorNestedWithinLHS.ts, 1, 14))
+>otherValue : Symbol(otherValue, Decl(narrowCommaOperatorNestedWithinLHS.ts, 0, 5))
+>value : Symbol(value, Decl(narrowCommaOperatorNestedWithinLHS.ts, 1, 5))
+>inner : Symbol(inner, Decl(narrowCommaOperatorNestedWithinLHS.ts, 1, 14))
+
+    const a = value.inner; // number
+>a : Symbol(a, Decl(narrowCommaOperatorNestedWithinLHS.ts, 8, 9))
+>value.inner : Symbol(inner, Decl(narrowCommaOperatorNestedWithinLHS.ts, 1, 14))
+>value : Symbol(value, Decl(narrowCommaOperatorNestedWithinLHS.ts, 1, 5))
+>inner : Symbol(inner, Decl(narrowCommaOperatorNestedWithinLHS.ts, 1, 14))
+
+    const b: number = (otherValue(), value).inner; // string | number , but should be number
+>b : Symbol(b, Decl(narrowCommaOperatorNestedWithinLHS.ts, 9, 9))
+>(otherValue(), value).inner : Symbol(inner, Decl(narrowCommaOperatorNestedWithinLHS.ts, 1, 14))
+>otherValue : Symbol(otherValue, Decl(narrowCommaOperatorNestedWithinLHS.ts, 0, 5))
+>value : Symbol(value, Decl(narrowCommaOperatorNestedWithinLHS.ts, 1, 5))
+>inner : Symbol(inner, Decl(narrowCommaOperatorNestedWithinLHS.ts, 1, 14))
+}
+
+if (isNumber((otherValue(), value).inner)) {
+>isNumber : Symbol(isNumber, Decl(narrowCommaOperatorNestedWithinLHS.ts, 1, 54))
+>(otherValue(), value).inner : Symbol(inner, Decl(narrowCommaOperatorNestedWithinLHS.ts, 1, 14))
+>otherValue : Symbol(otherValue, Decl(narrowCommaOperatorNestedWithinLHS.ts, 0, 5))
+>value : Symbol(value, Decl(narrowCommaOperatorNestedWithinLHS.ts, 1, 5))
+>inner : Symbol(inner, Decl(narrowCommaOperatorNestedWithinLHS.ts, 1, 14))
+
+    const a = value.inner; // number
+>a : Symbol(a, Decl(narrowCommaOperatorNestedWithinLHS.ts, 13, 9))
+>value.inner : Symbol(inner, Decl(narrowCommaOperatorNestedWithinLHS.ts, 1, 14))
+>value : Symbol(value, Decl(narrowCommaOperatorNestedWithinLHS.ts, 1, 5))
+>inner : Symbol(inner, Decl(narrowCommaOperatorNestedWithinLHS.ts, 1, 14))
+
+    const b: number = (otherValue(), value).inner; // string | number , but should be number
+>b : Symbol(b, Decl(narrowCommaOperatorNestedWithinLHS.ts, 14, 9))
+>(otherValue(), value).inner : Symbol(inner, Decl(narrowCommaOperatorNestedWithinLHS.ts, 1, 14))
+>otherValue : Symbol(otherValue, Decl(narrowCommaOperatorNestedWithinLHS.ts, 0, 5))
+>value : Symbol(value, Decl(narrowCommaOperatorNestedWithinLHS.ts, 1, 5))
+>inner : Symbol(inner, Decl(narrowCommaOperatorNestedWithinLHS.ts, 1, 14))
+}
diff --git a/tests/baselines/reference/narrowCommaOperatorNestedWithinLHS.types b/tests/baselines/reference/narrowCommaOperatorNestedWithinLHS.types
new file mode 100644
index 0000000000000..7ad1879002587
--- /dev/null
+++ b/tests/baselines/reference/narrowCommaOperatorNestedWithinLHS.types
@@ -0,0 +1,76 @@
+=== tests/cases/compiler/narrowCommaOperatorNestedWithinLHS.ts ===
+const otherValue = () => true;
+>otherValue : () => boolean
+>() => true : () => boolean
+>true : true
+
+const value: { inner: number | string } = null as any;
+>value : { inner: number | string; }
+>inner : string | number
+>null as any : any
+>null : null
+
+function isNumber(obj: any): obj is number {
+>isNumber : (obj: any) => obj is number
+>obj : any
+
+    return true; // method implementation irrelevant
+>true : true
+}
+
+if (typeof (otherValue(), value).inner === 'number') {
+>typeof (otherValue(), value).inner === 'number' : boolean
+>typeof (otherValue(), value).inner : "string" | "number" | "bigint" | "boolean" | "symbol" | "undefined" | "object" | "function"
+>(otherValue(), value).inner : string | number
+>(otherValue(), value) : { inner: string | number; }
+>otherValue(), value : { inner: string | number; }
+>otherValue() : boolean
+>otherValue : () => boolean
+>value : { inner: string | number; }
+>inner : string | number
+>'number' : "number"
+
+    const a = value.inner; // number
+>a : number
+>value.inner : number
+>value : { inner: string | number; }
+>inner : number
+
+    const b: number = (otherValue(), value).inner; // string | number , but should be number
+>b : number
+>(otherValue(), value).inner : number
+>(otherValue(), value) : { inner: string | number; }
+>otherValue(), value : { inner: string | number; }
+>otherValue() : boolean
+>otherValue : () => boolean
+>value : { inner: string | number; }
+>inner : number
+}
+
+if (isNumber((otherValue(), value).inner)) {
+>isNumber((otherValue(), value).inner) : boolean
+>isNumber : (obj: any) => obj is number
+>(otherValue(), value).inner : string | number
+>(otherValue(), value) : { inner: string | number; }
+>otherValue(), value : { inner: string | number; }
+>otherValue() : boolean
+>otherValue : () => boolean
+>value : { inner: string | number; }
+>inner : string | number
+
+    const a = value.inner; // number
+>a : number
+>value.inner : number
+>value : { inner: string | number; }
+>inner : number
+
+    const b: number = (otherValue(), value).inner; // string | number , but should be number
+>b : number
+>(otherValue(), value).inner : number
+>(otherValue(), value) : { inner: string | number; }
+>otherValue(), value : { inner: string | number; }
+>otherValue() : boolean
+>otherValue : () => boolean
+>value : { inner: string | number; }
+>inner : number
+}
diff --git a/tests/cases/compiler/narrowCommaOperatorNestedWithinLHS.ts b/tests/cases/compiler/narrowCommaOperatorNestedWithinLHS.ts
new file mode 100644
index 0000000000000..53e1891349e27
--- /dev/null
+++ b/tests/cases/compiler/narrowCommaOperatorNestedWithinLHS.ts
@@ -0,0 +1,16 @@
+const otherValue = () => true;
+const value: { inner: number | string } = null as any;
+
+function isNumber(obj: any): obj is number {
+    return true; // method implementation irrelevant
+}
+
+if (typeof (otherValue(), value).inner === 'number') {
+    const a = value.inner; // number
+    const b: number = (otherValue(), value).inner; // string | number , but should be number
+}
+
+if (isNumber((otherValue(), value).inner)) {
+    const a = value.inner; // number
+    const b: number = (otherValue(), value).inner; // string | number , but should be number
+}
\ No newline at end of file