Liverpool were able to score their fourth and decisive goal against Barcelona thanks to an alert ball boy who was instructed to help restart the game as swiftly as possible during the Champions League semi-final, British media reported on Thursday. Trent Alexander-Arnold's quickly-taken corner while Barcelona's defenders were still regrouping enabled an unmarked Divock Origi to fire home the goal that allowed Liverpool to advance to the final with a 4-3 aggregate win.