Merciless Bayern hit eight in Barcelona's shocking loss.

The ruthless Bayern Munich inflicted a devastating, record loss on Barcelona on Friday, posting a scarcely imaginable 8-2 win in their quarter-final Champions League in Lisbon, leaving Lionel Messi behind and surely rushing to the end of the Catalan age.

Thomas Mueller scored twice on either side of Ivan Perisic's and Serge Gnabry 's goals in a stunning 31-minute opening at the empty Stadio da Luz, with David Alaba's own goal bringing Barcelona back briefly.

Yet the tale of this game is the extraordinary capitulation of Barcelona, and the question is what happens to them right now.

Messi was 27 when they won the Champions League last time in 2015. He's 33 now and this game will make up his mind that he's actually going to leave Camp Nou if he's going to win it again.

Barca had only been here before: they were ripped apart by Bayern in the 2013 semi-finals, losing 7-0 overall, but that was 8 goals in 90 minutes.

And with an aging roster of six players aged 31 or older, this must be the end of the era.

Coach Quique Setien is not going to succeed. His side, having already finished second to Real Madrid in La Liga, clearly couldn't cope with the stress of Bayern.

Bayern went ahead in the fourth minute as Mueller managed a ball from the left by Perisic and played a one-two with Lewandowski to suffocate the low shot of former compatriot Marc-Andre ter Stegen.

They left themselves open at the back and balance was restored when Alaba, trying to avoid the cross of Jordi Alba, cut the ball over Manuel Neuer and into his own net.

For a very brief spell, Barca was also at the top, when Neuer was pressured into a crucial save from Suarez, and the Messi cross came back from the far upright.

But Bayern, suffocating their opponents with their pressing, went back in front midway through the first half. Gnabry won back possession on the edge of the final third before feeding Perisic, who fired past Ter Stegen and into the far corner.

That was the first of three goals in a 10-minute spell.

Leon Goretzka's deft touch over the top took out Clement Lenglet and Gnabry drilled home to make it 3-1. Then Mueller stole in front of Lenglet to turn in Kimmich's delivery from the right for 4-1.

Suarez briefly gave Barca something to cling to as he regulated Alba's ball from the left, swept away from Jerome Boateng, and shot at goal.

And there wouldn't be a turnaround, as Kimmich scored Bayern's fifth after Alphonso Davies' impressive assistance, and then he headed Coutinho's cross to make it six.

As Barcelona collapsed, Coutinho made it seven in the 85th minute at the end of the move, starting when Messi was robbed of possession, and then he had time to score another one in the 88th minute.
Luis Suarez brought it back to 4-2 at one point in the second half, but Barcelona then stalled, with Joshua Kimmich taking Bayern's fifth place out of three more goals in the final stages, one for the prolific Robert Lewandowski and two for Philippe Coutinho.

It was the most frustrating part of the defeated side, with Coutinho on loan from Barcelona to Bavaria, who spent a lot of money on signing the Brazilian in 2018.

The game was eerily reminiscent of Germany's 7-1 defeat of Brazil in the 2014 World Cup, a game that Mueller also played and scored.

Germany went on to win the World Cup, and Bayern seemed like a safe bet to win the Champions League, even if they're likely to face a tougher test in the semi-finals, whether they're facing Manchester City or Lyon.

This was their 19th consecutive victory in all competitions, and Hansi Flick's 28th unbeaten game. They scored 39 goals in the nine outings of the Champions League this year.