Liverpool ball boy an unlikely hero in their epic Barca comeback

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.

Liverpool analysts had watched how Barcelona players were always distracted when decisions went against them and word was passed down to Carl Lancaster, a coaching mentor at the club's academy, who asked the ball boys to serve their players quickly.

It was 14-year-old Oakley Cannonier who rolled a spare ball towards Alexander-Arnold when the Liverpool full back won a corner, even as the first ball bounced back into play.

As Origi kicked the stray ball off the pitch, nobody marked him. Even goalkeeper Marc-Andre ter Stegen was oblivious and still shouting instructions when the cross came in with Origi taking it first time to make it 4-0 and seal progress.

It was a cheeky goal that even drew praise from former Barcelona midfielder Cesc Fabregas. "People will tell me it's bad defending," he wrote on Twitter. "I'm telling you it's pure intelligence and vision."

Liverpool will play Tottenham Hotspur in the final in Madrid on June 1.