Stade Français had loosehead prop Zak Taulafo sent off as they collapsed to a 34-16 defeat at home to Racing 92 in Paris.
Taulafo's red card for a dangerous tackle on Chris Masoe left Racing momentarily down to 12 men with Sylvain Nicolas and Jono Ross already in the bin, as Racing ran away with the contest.
Morné Steyn opened the scoring in the first minute with a penalty for Stade and the first try also went the way of the hosts, Waisea Nayacalevu with the finish as Steyn converted for a 10-0 lead.
Dan Carter and Steyn traded penalties before Carter went over for Racing's first try, closing the gap. A third Stade penalty though meant the hosts were ahead 16-13 at the break.
After those two quick yellow cards Racing finally crossed again through scrum-half Mike Phillips, Goosen converting for a 20-16 lead.
With both Nicolas and Ross off Taulafo joined them following his straight red card allowing Racing to finish things off, with tries from Johan Goosen and Brice Dulin ensuring not just a win but also a bonus point for outscoring Stade four tries to one.
For Stade Français:
Pens: Steyn 3
Yellow Card: Nicolas, Ross
Red Card: Taulafo
For Racing 92:
Tries: Carter, Phillips, Goosen, Dulin
Cons: Carter, Goosen 3
Pens: Carter 2
Stade Français: 15 Djibril Camara, 14 Waisea Nayacalevu, 13 Geoffrey Doumayrou, 12 Jonathan Danty, 11 Jeremy Sinzelle, 10 Morné Steyn, 9 Julien Dupuy, 8 Jono Ross, 7 Willem Alberts, 6 Sylvain Nicolas, 5 Pascal Papé, 4 Hugh Pyle, 3 Paul Alo-Emile, 2 Laurent Sempere, 1 Zak Taulafo
Replacements: 16 Remy Bonfils, 17 Emmanuel Felsina, 18 Gerhard Mostert, 19 Patrick Sio, 20 Julien Tomas, 21 Meyer Bosman, 22 Hugo Bonneval, 23 Adrien Oleon
Racing 92: 15 Brice Dulin, 14 Joe Rokocoko, 13 Casey Laulala, 12 Alexandre Dumoulin, 11 Juan Imhoff, 10 Dan Carter, 9 Mike Phillips, 8 Antonie Claassen, 7 Luc Barba, 6 Yannick Nyanga Kabasele, 5 Francois van der Merwe, 4 Juandre Kruger, 3 Luc Ducalcon, 2 Dimitri Szarzewski,1 Julien Brugnaut
Replacements: 16 Virgile Lacombe, 17 Khatchik, Vartanov, 18 Thibault Dubarry, 19 Chris Masoe, 20 Xavier Chauveau, 21 Johan Goosen, 22 Albert Vulivuli, 23 Cedate Gomes Sa
Referee: Pascal Gauzère