Hoffenheim's dream first season in the Bundesliga continues to get better as it moved three points clear at the top with a 3-1 win at Cologne.
The league newcomer had begun the day level on points with Bayer Leverkusen, but now has daylight over its rivals who lost 2-1 at lowly Arminia Bielefeld.
Hoffenheim had taken a 1-0 lead into half-time, thanks to Demba Ba's 32nd-minute strike, before both teams had players sent off soon after the break.
Kevin McKenna was red-carded after 52 minutes for the hosts before Hoffenheim saw Luiz Gustavo given his marching orders four minutes later for a second bookable offence.
Hoffenheim took a two-goal lead after 67 minutes when the league's leading scorer Vedad Ibisevic netted, before Petit pulled a goal back in the 78th minute.
But Ibisevic struck again with two minutes left for his 16th goal of the season and Hoffenheim's seventh win from their past eight games.
Leverkusen's six-game unbeaten run was ended at Arminia, which took a two-goal lead through second-half strikes from its top scorer Artur Wichniarek (53) and substitute Daniel Halfar (68).
The visitors pulled a goal back through Patrick Helmes, who scored his first Germany goal in the 2-1 defeat to England in midweek, but their fate was sealed when Sascha Dum was sent off three minutes from the end.
The win was just Arminia's second of the season and moves it out of the drop zone.
Bayern Munich's steady rise up the table continues as it came from behind to beat bottom club Energie Cottbus 4-1.
Jurgen Klinsmann's side is now level on points with Leverkusen in third place, although its victory had looked less than assured when it went behind to a goal from Ervin Skela after 25 minutes.
It took Bayern just four minutes to reply, through France international Franck Ribery, before Martin Demichelis (38) headed it ahead going into the interval.
Further goals from strike duo Miroslav Klose (54) and Luca Toni (59) after the break sewed up a comfortable win for Bayern which could have won by more but for some fine stops from Cottbus goalkeeper Gerhard Tremmel.
Hertha Berlin reclaimed fourth place after it withstood a Bochum comeback to win 3-2.
The capital club took a three-goal lead into the break thanks to strikes from De Araujo Rafael (25), Gojko Kacar (33) and Santos Cicero (39).
But it almost threw that advantage away as half-time Bochum substitute Stanislav Sestak (50) and Marcin Miecel (74) moved it to within touching distance, only to fall narrowly short.
Eintracht Frankfurt was the biggest winner of the day as it thumped Hannover 4-0.
Nikos Liberopoulos struck twice either side of the break while Marco Russ and Martin Fenin were also on target.
Schalke bounced back from two tough defeats to ease past Borussia Monchengladbach 3-1 at home, with Halil Altintop bagging a brace.
The Turkey international struck in the 17th minute to open the scoring and Jefferson Farfan's penalty seven minutes later doubled the hosts' advantage.
Rob Friend cut the deficit to one goal after 30 minutes, but Altintop notched again on the stroke of half-time.
Wolfsburg was also a handsome winner as it beat Stuttgart 4-1 to pile more pressure on its under-fire boss Armin Veh.
Martin Lanig put Stuttgart ahead in the 17th minute, but two goals from Grafite in the 51st and 76th minutes turned the game around.
Edin Dzeko completed the rout with two late