Paris - Champions Toulouse withstood a valiant fightback from last year's finalists Biarritz to win a thrilling all-French European Cup quarterfinal 27-20 after extra time in San Sebastien on Sunday.
Despite Toulouse leading 17-0 at halftime, Biarritz levelled proceedings 17-17 to ensure the tie went into extra time before last year's winners prevailed to set up a semifinal rematch with Leinster who beat Leicester 17-10 in Dublin on Saturday.
It will be the tenth semifinal appearance for Toulouse who beat the Irish side at the same stage of the competition last season and have won the title four times - 1996, 2003, 2005, 2010.
A try from substitute Congolese flanker Yannick Nyanga in the final minutes of extra time allowed Toulouse to snatch the victory.
Biarritz had managed to come back from a 17-point deficit as Toulouse had a perfect first half with tries from Cedric Heymans and Maxime Medard, converted by David Skrela and Nicolas Bezy, with Bezy also kicking a penalty.
But Biarritz clawed their way back thanks to four penalties from the boot of Dimitri Yachvili and a try from winger Ilikena Bolakoro two minutes from time.
Both sides scored penalties in extra time through Skrela and Yachvili before Nyanga's match-winner.