diff --git a/sizzle.js b/sizzle.js
index 66c5acbb..e12b45fc 100644
--- a/sizzle.js
+++ b/sizzle.js
@@ -12,8 +12,10 @@ var i,
 	getText,
 	isXML,
 	compile,
-	hasDuplicate,
 	outermostContext,
+	hasDuplicate,
+	sortInput,
+	sortInputOriginal,
 
 	// Local document vars
 	setDocument,
@@ -588,26 +590,45 @@ setDocument = Sizzle.setDocument = function( node ) {
 	// Document order sorting
 	sortOrder = docElem.compareDocumentPosition ?
 	function( a, b ) {
-		var compare;
-
+		// Short-circuit on node equality
 		if ( a === b ) {
 			hasDuplicate = true;
 			return 0;
 		}
 
-		if ( (compare = b.compareDocumentPosition && a.compareDocumentPosition && a.compareDocumentPosition( b )) ) {
-			if ( compare & 1 || a.parentNode && a.parentNode.nodeType === 11 ) {
+		var compare = b.compareDocumentPosition && a.compareDocumentPosition &&
+			a.compareDocumentPosition( b );
+
+		if ( compare ) {
+			// Detect disconnected nodes
+			if ( compare & 1 ||
+				// Support: Opera, Firefox
+				// Results can't be trusted for document fragment children
+				a.parentNode && a.parentNode.nodeType === 11 ||
+				// Support: Webkit
+				// Detached nodes confoundingly follow *each other*
+				compare === b.compareDocumentPosition( a ) ) {
+
+				// Prioritize our document
 				if ( a === doc || contains( preferredDoc, a ) ) {
 					return -1;
 				}
 				if ( b === doc || contains( preferredDoc, b ) ) {
 					return 1;
 				}
-				return 0;
+
+				// Maintain relative order if neither node is in our document (jQuery #13331)
+				if ( sortInputOriginal ) {
+					sortInput = slice.call( sortInput, 0 );
+					sortInputOriginal = false;
+				}
+				return indexOf.call( sortInput, a ) - indexOf.call( sortInput, b );
 			}
+
 			return compare & 4 ? -1 : 1;
 		}
 
+		// Not directly comparable; sort on existence of the method
 		return a.compareDocumentPosition ? -1 : 1;
 	} :
 	function( a, b ) {
@@ -618,7 +639,7 @@ setDocument = Sizzle.setDocument = function( node ) {
 			ap = [ a ],
 			bp = [ b ];
 
-		// Exit early if the nodes are identical
+		// Short-circuit on node equality
 		if ( a === b ) {
 			hasDuplicate = true;
 			return 0;
@@ -744,6 +765,7 @@ Sizzle.uniqueSort = function( results ) {
 
 	// Unless we *know* we can detect duplicates, assume their presence
 	hasDuplicate = !support.detectDuplicates;
+	sortInput = sortInputOriginal = results;
 	results.sort( sortOrder );
 
 	if ( hasDuplicate ) {
diff --git a/test/unit/utilities.js b/test/unit/utilities.js
index 6094f548..9c606306 100644
--- a/test/unit/utilities.js
+++ b/test/unit/utilities.js
@@ -44,7 +44,7 @@ if ( jQuery("<svg xmlns='http://www.w3.org/2000/svg' version='1.1' height='1' wi
 }
 
 test("Sizzle.uniqueSort", function() {
-	expect( 12 );
+	expect( 14 );
 
 	function Arrayish( arr ) {
 		var i = this.length = arr.length;
@@ -59,6 +59,7 @@ test("Sizzle.uniqueSort", function() {
 	};
 
 	var i, tests,
+		detached = [],
 		body = document.body,
 		fixture = document.getElementById("qunit-fixture"),
 		detached1 = document.createElement("p"),
@@ -66,8 +67,10 @@ test("Sizzle.uniqueSort", function() {
 		detachedChild = detached1.appendChild( document.createElement("a") ),
 		detachedGrandchild = detachedChild.appendChild( document.createElement("b") );
 
-	for ( i = 0; i < 4; i++ ) {
-		detached2.appendChild( document.createElement("li") ).id = "i" + i;
+	for ( i = 0; i < 12; i++ ) {
+		detached.push( document.createElement("li") );
+		detached[i].id = "detached" + i;
+		detached2.appendChild( document.createElement("li") ).id = "detachedChild" + i;
 	}
 
 	tests = {
@@ -87,7 +90,11 @@ test("Sizzle.uniqueSort", function() {
 			input: [ body, fixture, fixture, body ],
 			expected: [ body, fixture ]
 		},
-		"Detached elements": {
+		"Detached": {
+			input: detached.slice( 0 ),
+			expected: detached.slice( 0 )
+		},
+		"Detached children": {
 			input: [
 				detached2.childNodes[0],
 				detached2.childNodes[1],