Exequiel Palacios, the World Cup champion of Argentina, Bayer Leverkusen scored twice from the penalty spot. He was stunned by Bayern Munich 2-1 on Sunday to open up the Bundesliga title race completely.
Leverkusen overcame a deficit with some assistance from VAR to give coach Xabi Alonso a notable victory on his first meeting with former team Bayern and prevent the champions from regaining the top spot.
Borussia Dortmund, who now leads the league, and Bayern are due to square off on April 1 in the upcoming round of games.
Bayern forward Thomas Mueller told Dazn, "We are not where we wanted to be heading into that game.
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"Today we deserved to lose. He continued; Leverkusen was better against the ball and had more bite".
Jeremie Frimpong had an early opportunity for the champions. Still, they managed to hold on before Odilon Kossounou deflected a shot from Joshua Kimmich into his own goal to give them the lead.
However, the home team continued to pose challenges for Bayern, and they thoroughly deserved their equalizing penalty kick in minute 55.
Amine Adli was first cited for diving when Benjamin Pavard clipped him, but the VAR overturned the ruling, and Palacios scored right away.
- Union Recover -
In other matches, Union Berlin improved their chances of qualifying for the Champions League by defeating Bundesliga top-six opponents Eintracht Frankfurt 2-0 thanks to a rare goal from Rani Khedira.
Brother of the World Cup champion Sami Khedira, who scored the game's first goal, lifted Union back into third position with his eighth goal in 194 Bundesliga games.
I'm thrilled since it's also my first goal for Union, Khedira told Dazn. Today's battle was much more about mindset than it was about strategy.
Both teams entered the match with five-game losing streaks and were looking to avenge midweek elimination from European play.
While Union reverted to their signature counter-attacking strategy in the first half, Frankfurt had most of the chances.
With three headers, Randal Kolo Muani touched the woodwork, while Daichi Kamada compelled in-form Union goalkeeper Frederik Ronnow to make a commendable save.
Yet after Frankfurt failed to clear a corner, the home team scored first when Khedira punched the ball in from close range.
In the 69th minute, Union's Sheraldo Becker nutmegged Frankfurt goalkeeper Kevin Trapp to score again, but the goal didn't stand for offside.
Trapp allowed the ball to slip through his legs again a few minutes later, allowing Kevin Behrens to double the advantage.
Union are three points ahead of RB Leipzig in third place in the league after going 18 straight home games without a loss.