Jo-Wilfried Tsonga has branded his French Open quarter-final win over Roger Federer as "extraordinary".

The Frenchman ensured his spot in the final four with a three-set win over Federer on Tuesday, but he has admitted that he is wary of semi-final opponent David Ferrer.

"It's extraordinary to be here and to have won. I never dreamt of this moment. Today was my moment against a champion who has won everything," he told reporters following the match.

"I didn't think I would get this far without losing a set. But Ferrer has not lost a set as well, he's in great form."

Tsonga is yet to win a Grand Slam.