Relegation-threatened Energie Cottbus struck twice in the second half to stun Bundesliga leaders VfL Wolfsburg 2-0 on Sunday and cut their lead to two points with five matches left.
Hosts Cottbus grabbed the first goal against the run of play in the 72nd minute when unmarked Dimitar Rangelov headed in an Ivica Iliev cross at the far post.
Ervin Skela added a second four minutes from time to seal the win that lifts them to 15th place.
Wolfsburg, who saw their record-equalling 10-match winning streak in the league end abruptly, are now two points ahead on 57, after Hertha Berlin moved back into second place with a gutsy 1-0 win over Hoffenheim on Friday.
Wolfsburg coach Felix Magath again refused to speculate about a possible title win, saying their aim was a top-five finish.
"We missed our chances today and that is why we did not win," Magath told reporters. "Our strikers did not have a good day. Our aim remains the fifth spot and there our prospects look good."
Champions Bayern Munich dropped to third, a point behind, after losing at home to Schalke 04 1-0 on Saturday.
VfB Stuttgart scored once in each half to beat Eintracht Frankfurt 2-0 and join Bayern, while Hamburg SV were also stuck on 54, fifth on goal difference, after their 2-0 defeat against Borussia Dortmund on Saturday.
In the other match on Sunday Arminia Bielefeld and Borussia Moenchengladbach settled the relegation derby with a point each by drawing 1-1.
Cottbus surprised the visitors with disciplined attacks, coming forward in search of an early opener, but failed to set up lone striker Rangelov on several occasions.
Wolfsburg had their first real chance after 17 minutes when Zvjezdan Misimovic released a shot that Cottbus keeper Gerhard Tremmel punched into the path of Grafite who fired over the bar from seven metres.
Again and again the visitors tried to take advantage of Edin Dzeko's speed, seeking the striker with deep passes, but a well-positioned Cottbus defence made the breakthrough difficult.
The Bosnian got his chance minutes before the break when he raced towards Tremmel, after picking up a long pass, but his shot sailed inches wide.
Cottbus looked to be running out of attacking steam early in the second half, allowing Wolfsburg to gain more space in midfield to launch their quick attacks. But the hosts' defence held tight as they gradually grew in confidence.
That paid off when Albanian Skela combined well with Iliev who sent in a cross for the lurking Rangelov to score his ninth goal of the season.
Skela then turned scorer in the 86th minute, chasing a good through ball to slot home from inside the box.