Bayern Munich humiliated Tottenham with an incredible 7-2 win in Champions League Group B on Tuesday.

Here’s a look at three things we learned from the remarkable clash at the Tottenham Hotspur Stadium:

Pain for Pochettino

Having accused his under-performing Tottenham stars of “different agendas” following their shock League Cup defeat at Colchester last week, manager Mauricio Pochettino endured another chastening result that underlined the impression all is not well with last season’s Champions League runners-up.

Pochettino is convinced Tottenham’s season has been destabilised by a group of players who have been distracted by speculation over potential transfers.

Christian Eriksen, Jan Vertonghen, Toby Alderweireld, Danny Rose and Victor Wanyama were all linked with moves before the transfer window closed and they remain far from certain to stay past the end of the season.

With just three wins from 10 games in all competitions, there is no doubt Tottenham are in turmoil.

And the sight of Pochettino’s team surrendering as Bayern became the away team ever to score seven at Tottenham in any competition suggests Pochettino faces a massive task to turn the tide.

Tottenham’s incredible run to their first Champions League final last term came despite a wretched start to the group stage and, with only one point from two games, once again they will have to defy the odds to reach the last 16.

Gnabry makes stylish return

Former Arsenal winger Serge Gnabry made a memorable return to north London as the German winger’s four-goal blitz inspired Bayern’s swaggering success.

A serious knee injury meant Gnabry didn’t make much of an impact in his 18 games for Arsenal between 2012 and 2016 after arriving from the Stuttgart academy.

He fared no better during a frustrating loan spell at West Brom, but his career has taken off in spectacular fashion since moving to Werder Bremen three years ago.

“It was the hardest decision I had to make in football, leaving a club like Arsenal – the fans, the players – but to keep playing I had to take a step back and it was the right decision,” Gnabry said recently.

Gnabry joined Bayern in 2017 and was voted their player of the year last season while establishing himself in the German national team.

Back in familiar surroundings in London, the 24-year-old showed how much he has improved by putting Bayern 3-1 up as he beat Serge Aurier and Toby Alderweireld before smashing into the bottom corner.

Gnabry wasn’t finished yet and his second goal was another clinical effort as he drilled past Hugo Lloris.

Taking advantage of Aurier’s terrible positional play, Gnabry sprinted clear to complete his treble in the 83rd minute before capping a cathartic visit to the capital with his fourth five minutes later.

Alli fails to take his chance

Dele Alli was a surprise inclusion in the Tottenham team as the out-of-form England midfielder made just his fourth appearance this season.

But once again it was a frustrating night for Alli, who failed to seize his unexpected chance to get back in Pochettino’s good books.

Alli’s anonymous effort allowed Bayern to take control in midfield as they dominated the second half and he was hauled off on 70 minutes.

It continued a dismal stretch for Alli, who has been in a steady decline since he last scored in the Champions League in Tottenham’s famous 2017 group-stage win over Real Madrid.

Back then, it was hard to imagine Alli being in a fight to save his Tottenham career, but his future looks increasingly cloudy after another badly-timed flop following his woeful effort in the loss at Colchester.