Paris - Struggling French Top 14 champions Stade Francais crashed to a seventh defeat of a testing season as they were beaten 25-12 at bottom side Oyonnax on Sunday.
Oyonnax were coming off three successive lopsided losses but climbed off the foot of the table as the boot of Regis Lespinas accounted for 17 points with Jimmy Yobo scoring the game's only try.
Stade face an increasingly difficult challenge to defend their crown having won just four of 11 matches this term, a series of results that has left the capital club just three places off the bottom.
Stade flyhalf Morne Steyn and his Oyonnax counterpart Lespinas knocked over three penalties apiece as the sides went into the interval level at 9-9 on the artificial surface at the Stade Charles-Mathon.
South African Steyn booted another penalty to give Stade a 12-9 lead early in the second half, but it was all Oyonnax from that point onwards.
The hosts benefitted from a huge stroke of good fortune shortly after when Lespinas struck the upright with a penalty, only for the ball to bounce back to Yobo who touched down to put Oyonnax ahead, with Lespinas adding the conversion.
Lespinas added two further penalties to give the home side breathing space before Quentin Etienne slotted over from close to 50 metres out as Stade's cause was hampered by the sin-binning of full-back Djibril Camara