Leipzig scored five times in the second half to come from behind and beat Stuttgart 5-1 for their first Bundesliga win of the season.
Goals from Benjamin Henrichs, Dani Olmo, Loïs Openda, Kevin Kampl and Xavi Simons on Friday came after the home team was aggrieved for not being awarded a penalty at the end of the first half.
Serhou Guirassy, who put Stuttgart ahead in the 35th minute, brought down Leipzig captain Willi Orbán from behind after falling into him.
But Guirassy had been pushed by Yussuf Poulsen and referee Frank Willenborg awarded a free kick for the Leipzig forward's foul - a decision upheld after a video check.
Leipzig coach Marco Rose was booked for his furious reaction and was still arguing as he departed down the players' tunnel, then apparently used that anger to rouse his players during the interval.
Stuttgart goalkeeper Alexander Nübel, who joined on loan from Bayern Munich in the offseason, endured a second half to forget after impressing in the first.
Nübel's attempted kickout was charged down by Henrichs for the equaliser in the 61st, before another mistake gifted Openda a goal two minutes later that was ruled out by VAR for offside.
It was only a brief respite for Stuttgart as Olmo put Leipzig ahead in the 63rd and the home team pushed on from there.
"We started well into the second half and got a deserved win. That was fun. We know what we are capable of. We have confidence," Leipzig captain Orban told streaming portal DAZN.
Leipzig, who finished third last season, started the league with a 3-2 loss at Bayer Leverkusen last weekend, while Stuttgart opened with a 5-0 rout of Bochum.
"It was a brutal game, a brutal evening. In the end it is bitter to lose 5-1. It hurts a lot," said Stuttgart No.1 Nübel said.