A first ever top-flight goal for 19-year-old Jonathan Burkardt saw German minnows Mainz all but secure Bundesliga survival with a surprise 2-0 victory at Borussia Dortmund on Wednesday.
Local boy Burkardt, making only his second start of the campaign, gave his side a shock lead when he headed in Ridle Baku's cross after a drab first half hour.
"I told Jonny before the game to believe in this chance. He's a very hard-working guy, his heart is in the right place, but he has had to be patient this season," Mainz coach Achim Beierlorzer told Sky.
The goal sparked a season-saving performance for Mainz, who later doubled the lead through a Jean-Philippe Mateta penalty to put clear daylight between themselves and the drop zone.
"These three points are worth double. It's not over yet but we took a huge step in the right direction," Mainz defender Jean-Paul Boetius said.
With Champions League qualification secured and Bayern already crowned champions, second-placed Dortmund had little to play for, and they barely threatened the visitors' goal as the clock ticked down.
With two games still to play, Mainz now have a five-point lead over the bottom three after Fortuna Duesseldorf snatched a late 2-2 draw at RB Leipzig
Two curling strikes from Kevin Kampl and Timo Werner appeared to have condemned Duesseldorf to the bottom three, but late goals from Steven Skrzybski and Andre Hoffmann saw Uwe Roesler's side rescue a crucial point late on.
They remain third from bottom in the relegation play-off place, just a single point above Werder Bremen in the race to avoid automatic relegation.
Elsewhere, Bayer Leverkusen broke back into the top four with a 3-1 win over local rivals Cologne.
Sven Bender turned in a low corner from Leon Bailey at the near post to give Leverkusen an early lead, and talisman Havertz added a second shortly before half-time.
Sebastiaan Bornauw's second-half header gave Cologne brief hope, but it was extinguished late on by a fine individual goal from Moussa Diaby.
The race for the Champions League remains finely poised, with just a single point separating Leverkusen and fifth placed Borussia Moenchengladbach ahead of the final two games.
- Further Wagner woes -
Earlier, a 2-1 defeat away to Eintracht Frankfurt saw David Wagner's Schalke side extend their winless streak to 14 games.
A new club record as of last weekend, the dismal run has seen Schalke plummet from the top four to mid-table.
Goals either side of half time from Andre Silva and David Abraham saw a dominant Frankfurt take a comfortable two-goal lead, before US international Weston McKennie headed Schalke back into the game on the hour mark.
While Schalke continue to sink, Frankfurt are hoping to make a late charge for European qualification. They now sit four points behind the coveted seventh spot.
"Our aim has to be to pick up six points and hope that the two teams ahead of us slip up," Frankfurt midfielder Sebastian Rode told broadcaster DAZN.
Yet it is Hoffenheim who now look the favourites to claim the final Europa League spot, after they fought to a 3-1 win over Augsburg on Wednesday.
A quickfire brace from Munas Dabbur and a late prod from Ihlas Bebou were enough to take the three points from Augsburg, who were given brief hope by Ruben Vargas' second-half header.
Mainz' Jonathan Burkardt celebrates his first Bundesliga goal
David Wagner was appointed Schalke boss in July last year