Ingolstadt moved out of the bottom two on Sunday with a surprise 2-1 win at Bayer Leverkusen.
The visitors took the lead in the 26th minute with a powerful Alfredo Morales header from Markus Suttner's cross, prompting the first chorus of whistles from the BayArena faithful.
Those grew in intensity when the half-time whistle was blown with Leverkusen not having looked like crafting an equaliser.
Things took another turn for the worse for Leverkusen early in the second half when Charles Aranguiz picked up his second yellow card of the game to leave his side with 10 men for over 40 minutes.
Almog Cohen missed a glorious opportunity to double Ingolstadt's lead in the 62nd minute and it came back to haunt him when Admir Mehmedi brought Leverkusen level with a deflected shot just a minute later.
Cohen had the last laugh, though, when he made up for his earlier error to earn Ingolstadt victory and spark another round of jeers from the home fans.
ends