Argentina's World Cup winner Exequiel Palacios struck twice from the spot as Bayer Leverkusen blew the Bundesliga title race wide open with a shock 2-1 win over Bayern Munich on Sunday.
With a little help from VAR, Leverkusen came from behind to hand coach Xabi Alonso a famous win on his first reunion with former club Bayern and keep the champions from regaining top spot.
"It's an unbelievable feeling. I'm so proud of the way we played today," said Alonso, who played for Bayern from 2014 to 2017.
Bayern are a point behind leaders Borussia Dortmund and the two sides set to meet in the next round of games on April 1.
"That is now a must-win game for us, because it will be very difficult to win the title otherwise," said Bayern coach Julian Nagelsmann.
"It was a deserved defeat today. Apart from the last 10 minutes, they were the better team," he added.
Bayern sporting director Hasan Salihamidzic was scathing in his criticism of the performance.
"We let ourselves be overrun by a team who played in midweek. That's not what it means to be Bayern Munich," he said.
"VAR was a lifesaver today and it was a perfect example of how the system should work," said referee Tobias Stieler.
The win also kept Leverkusen afloat in the race for Europe, with Alonso's side now just three points adrift of sixth.
Elsewhere, Union Berlin gave their Champions League hopes a boost as a rare goal from Rani Khedira helped them to a 2-0 win over Bundesliga top-six rivals Eintracht Frankfurt.
Khedira — the brother of 2014 World Cup winner Sami — stabbed in the opener to score only his seventh goal in 194 Bundesliga appearances and lift Union back into third place.
"It's also my first goal for Union so I am very happy," Khedira told Dazn. "Today was much more about mentality than about tactics."