Ospreys (6) 15
Pens: Biggar 5
Perpignan (9) 9
Pens: Porical 3
Ospreys' Shane Williams is tackled by Rimas Alvarez Kairelis.
Teenage fly-half Dan Biggar saved the Ospreys' blushes as the Welsh region struggled to Heineken Cup victory against an indisciplined Perpignan.
Three visitors were sin-binned and they were down to 13 at one point in the first half.
The hosts took the lead in the 65th minute as Biggar, 19, won his kicking duel with Jerome Porical.
Perpignan got a losing bonus point as Gavin Henson watched from the bench on his early return from a two-match ban.
Porical opened the scoring after the Ospreys' shaky start. Shane Williams knocked on and when Nicolas Mas charged forward, Alun Wyn Jones launched an illegal tackle, then failed to roll away from the breakdown.
That left full-back Porical with the simplest of penalty shots, which he converted after two minutes.
The hosts peppered Perpignan with tactical kicks in the opening minutes, but in the absence of James Hook, who suffered a back spasm which forced him out of the side, their execution was often poor.
However, Perpignan had problems of their own with makeshift fly-half David Mele, usually a scrum-half, replaced in the 12th minute by a fellow scrum-half in Nicolas Durand amid their own injury crisis.
When Lee Byrne was caught in possession six minutes later, Porical added his second penalty - this time from wide on the right.
From the restart visiting centre Christophe Manas killed the ball and fly-half Biggar kicked their first points.
Biggar could not level after another Perpignan transgression, but after 25 minutes wing Adrien Plante tackled Byrne while the full-back was in the air to earn 10 minutes in the sin-bin.
Biggar drew the sides level after 29 minutes with his third penalty attempt, but Porical soon put the visitors back in front after scrum-half Rhys Webb was caught offside.
Ospreys prop Paul James could be cited after he was caught on camera sending hooker Marius Tincu to the floor with a punch, an incident not spotted by the match officials.
After Wyn Jones was dragged down two metres short, Perpignan flanker Jean-Pierre Perez strayed offside and followed Plante to the sin-bin thanks to referee Wayne Barnes' second yellow card.
But the hosts could not take advantage of a depleted opposition with the home forwards unable to deliver possession deep in Perpignan territory and Ryan Jones' side ended the half 9-6 down.
A storming Ian Evans run after 48 minutes gave Huw Bennett the chance to use an overlap, but the hooker wasted the chance.
There was more frustration for the hosts when Filo Tiatia sent Webb through the middle of the line-out and clear to the line only for referee Barnes to penalise Ospreys skipper Jones for obstruction.
When Perpignan fell offside after the hosts' best period of pressure, Biggar kicked the penalty to draw level, but that was scant reward for their efforts.
The young fly-half put his side in front for the first time in the 65th minute after Evans caught Chris Cusiter in possession and the scrum-half failed to release the ball.
Perpignan saw their third man sin-binned when replacement forward Guillaume Vilaceca killed the ball in a tackle deep in his side's 22 and Biggar kicked his fifth and final penalty.
Ospreys: Byrne, Vaughton, Bowe, A. Bishop, Williams, Biggar, Webb, James, Bennett, A. Jones, Wyn-Jones, Evans, R. Jones, Holah, Tiatia.
Replacements: D. Jones for James (53), Hibbard for Bennett (72), Gough for Wyn-Jones (69), Smith for R. Jones (80).
Not Used: Lloyd, D. Bishop, Henson.
Perpignan: Porical, Plante, Sid, Manas, Candelon, Mele, Cusiter, Freshwater, Tincu, Mas, Olibeau, Alvarez, Perez, Britz, Chouly.
Replacements: Durand for Mele (11), Guirado for Freshwater (55), Pulu for Tincu (55), Guiry for Olibeau (59), Vilaceca for Alvarez (55), Vaki for Perez (69).
Not Used: Burger.
Sin Bin: Plante (25), Perez (33), Vilaceca (72)
Ref: Wayne Barnes (England)