Stade Francais will host Bath in the semi-finals of the European Challenge Cup after winning 25-21 against Ospreys, despite Josaia Raisuqe's dismissal.
Following a scrappy start at Cardiff's Principality Stadium, Dan Biggar squeezed a kick between the posts to break the deadlock after 12 minutes and a TMO review denied Biggar a try moments later, as the final pass from Keelan Giles was deemed to be forward.
Stade wing Raisuqe was lucky to be shown only a yellow card for a stamp on Giles in the 19th minute but Ospreys could not make their man advantage count during his spell on the sidelines and Jules Plisson kicked the visitors level before Stade prop Zurabi Zhvania crossed to put his side in front.
Biggar reduced the deficit but Plisson should have restored Stade Francais' five-point lead before half-time, somehow missing a simple kick, leaving the score 8-6 in the visitors' favour at the interval after Biggar struck the woodwork with his own straightforward effort.
Josh Matavesi's try survived another TMO review for a forward pass to get the Welsh side level at 11-11 and after Dan Baker kicked Ospreys ahead, Raisuqe was dismissed for a second yellow card to seemingly give the hosts a major advantage.
But catastrophic Ospreys defending allowed Raphael Lakafia and Julien Arias to score a pair of quickfire tries to make the score 25-14 and although replacement Tyler Ardron squeezed over a converted try to reduce the deficit to four points with three minutes remaining, Stade Francais held on to book a semi-final berth.