1. FC Union Berlin took revenge for the bitter cup loss at RB Leipzig and inflicted a heavy defeat on the unloved rival in the fight for the Champions League.
The Irons turned the Bundesliga game in just three minutes in a 2-1 (0-0) win.
Three days after the defeat in the cup semifinals, Union ended the Saxons' run of 15 unbeaten games.
In front of 45,770 spectators in the Red Bull Arena, Yussuf Poulsen (46th) scored the lead on Saturday before Sven Michel (86th) equalized just 21 seconds after coming on as a substitute.
A little later, substitute Kevin Behrens (89th) ensured the away win.
RB suffered a major setback in the fight for the premier class qualification and is unsure about the semi-final first leg of the Europa League this Thursday against Glasgow Rangers.
In the second duel in three days against the Irons, Domenico Tedesco brought fresh strength and made a total of six changes.
Winning goal scorer Emil Forsberg was allowed to play for Dominik Szoboszlai from the start.
Union coach Urs Fischer, who had to do without Timo Baumgartl, who was suspended, made three changes.
In addition, despite the return of Andreas Luthe, Fischer committed himself to Fredrik Rönnow as keeper, perhaps even until the end of the season.
"It's not easy for Andi, but he accepted it athletically."
Fischer wanted to get the cup knockout out of his head and "remember the good actions".
That's how union began.
Taiwo Awoniyi forced RB keeper Peter Gulacsi to do a class reflex after just 88 seconds.
After that, in contrast to the cup game, there was a lot of idle time.
Both lines of defense neutralized each other.
Shortly before the change, the Köpenickers had the lead on the foot: Gulacsi again brilliantly responded to the shot from Grischa Prömel (44th) from close range.
Then the runner-up was lucky: a brilliant long-range shot by Christopher Trimmel only hit the crossbar.
RB also set a minus record.
Never before has a team gone two games in a row without a chance to score in the first half.
In the second half, the Saxons woke up.
The ball was played immediately after kick-off, Christopher Nkunku crossed into the penalty area, where Prömel initially cleared with a header, Poulsen (46th) took the ball directly and hit the bottom left corner.
Union was unlucky again.
After a shot by Niko Gießelmann, Nordi Mukiele hit the Unioner in the leg while blocking.
Referee Daniel Schlager checked the TV action, but refused a penalty.
Mukiele (73rd) had the 2-0 for Leipzig on his feet, but only hit the post.
Then Union struck back: after a Becker cross, substitute Michel (86th) hit with a pike header to make it 1-1 before he hoeed Behrens three minutes later.
This converted with a placed low shot to 2: 1, the 2500 Union fans in the guest block celebrated exuberantly.