Full-back Jerome Porical kicked 20 points as Stade Francais booked their place in the Amlin Challenge Cup final with a narrow 25-22 win over Perpignan at the Stade Aime Giral.
Perpignan were leading going into the closing minutes of the all-French semi-final but two long-range penalties for Porical saw Stade over the line and they will now face either Leinster or Biarritz, who play each other at the RDS in Dublin on Saturday.
Stade took an early lead through Porical's boot but soon the home side were in front thanks to tries from hooker Guilhem Guirado and Welshman James Hook.
Hook missed both conversions before he slotted one penalty to Porical's two as USAP took a 13-9 lead into half-time.
After the break, two more Hook penalties sandwiched Stade's only try of the game, which came thanks to former Scarlets number eight David Lyons.
Porical continued to make hay against his former club and slotted the conversion, before he again traded penalties with Hook, who missed three other attempts on goal in the second half.
With the clock ticking down Perpignan were three points ahead and looked to be edging into next month's final in Dublin.
However, a 74th-minute penalty to draw level before the final hammer blow three minutes before the final whistle ensured it would be the 2010/11 Amlin Cup runners-up who will play for their first piece of European silverware on 17 May.