(CNN) -- Bayern Munich had Franck Ribery sent off in the second half as they slipped to a 1-0 home defeat to Schalke 04 which dents their Bundesliga title hopes.
Schalke's overjoyed players celebrate Altintop's winning goal.
Under-fire coach Juergen Klinsmann was jeered by Bayern fans at the Allianz Arena as they remained three points adrift of leaders VfL Wolsburg, who can stretch their advantage with victory over Energie Cottbus on Sunday.
Hertha Berlin have moved above them into second place after a 1-0 win over Hoffenheim on Friday night, but SV Hamburg's championship hopes suffered a setback as they lost 2-0 at Borussia Dortmund.
Hamburg went behind to a Sebastian Kehl goal after 32 minutes with Swiss international Alexander Frei grabbing the second from the spot in injury time.
Charging VfL Stuttgart are up to fourth in the table as Cacau and Mario Gomez scored in the 2-0 win over Eintracht Frankfurt.
Defending champions Bayern fluffed their chance to make headway in the five-team title race as they went down to a goal by Schalke's Turkish international Halil Altintop after 21 minutes.
Both teams had men sent off after the break with Schalke's Jermaine Jones the first to go in the 70th minute for his second yellow card.
French international Ribery was shown red six minutes later again for two yellows.
Former German international coach Klinsmann has been under mounting pressure since Bayern's heavy Champions League quarterfinal defeat to Barcelona mixed with indifferent league form.