Bayer Leverkusen must treat their dramatic victory over Wolfsburg as a "huge wake-up call", so says Granit Xhaka. 

Bundesliga champions Leverkusen pulled off a stunning comeback to win 4-3 on Sunday.

Victor Boniface scored a 93rd-minute winner, with Leverkusen having to come from 3-2 down after Wolfsburg scored twice in the space of nine minutes at the end of the first half.

And Xhaka, who assisted Florian Wirtz's 14th-minute goal to cancel out Wolfsburg's early opener, knows there is plenty of room for improvement.

"This is a huge wake-up call for all of us. We can't continue with this performance," Xhaka told DAZN.

"We can't defend so naively. That's not good enough and shouldn't happen at this level. A top team doesn't concede two goals in nine minutes! It was all far too easy."

Xabi Alonso's men have now conceded nine goals in the league, and are the first defending champions to go without a clean sheet in the first four Bundesliga games of the season since Kaiserslautern in 1998-99.

Boniface, meanwhile, looked on the brighter side.

"We knew how Wolfsburg would play and what we were up against," he said.

"We really wanted to turn the game around for our fans.

"We managed to do that. Now, of course, we're very happy."