Watch: Liverpool's Cheeky 4th Goal That Stumped Barcelona and Dumped Them Out of Champions League

Barcelona had come to Anfield vary but confident after registering a solid 3-0 win over Liverpool in the first leg of the UEFA Champions League at Camp Nou last week.

But their world was turned upside down with the intensity, intent, desire and passion that Liverpool put in each movement of theirs on Tuesday in front of their vociferous fans to snatch the victory.

Lionel Messi had said after the first leg that he would have liked a 4-0 lead but surely they were confident of scoring at least one at Anfield to shut the door for Liverpool.

That never happened and instead, Liverpool scored their first in the 7th minute through Divock Origi.

Barcelona were taken aback by the pace and intensity that Liverpool put early on and conceded. They managed to hold on for the rest of the first half but second half was one for the ages for Liverpool.

1-0 became 2-0 after Georginio Wijnaldum scored a skillful goal. Exactly two minutes later, the scoreline had become 3-0 and Barcelona were stunned.

But it was the fourth goal that caught everyone's eye.

Alexander-Arnold was with the ball standing at the corner flag. With the ball at the line, he took a couple of steps into the pitch and noticed Barcelona were not ready.

He ran and quickly delivered the corner kick towards Origi, who slotted it home. And just like Barcelona were caught completely off guard.

That moment in the 79th minute, Liverpool found themselves leading 4-3 on aggregate and had made the comeback from a massive 3-0 deficit.

Barcelona were completely lost and shocked to the core. They tried to go up but Liverpool did extremely well to keep everyone at bay - kept the position, maintained their intensity and closed down extremely well at the back.

It was destined to be a special Anfield European night.

Alexander-Arnold, the taker of 'that' Liverpool goal later said that it was completely instinctive and it was good on Origi to be switched on to finish the job.

"I think it was just instinctive," Alexander-Arnold told BT Sport. "It was just one of those moments where you see the opportunity and obviously Div was switched on to finish it off.

"It probably came at him a bit fast but he's a top player, scored two goals for us tonight and I think it's one of them where everyone will remember this moment."