METZ, France (AP)—Gilles Muller of Luxembourg upset second-seeded Richard Gasquet of France 6-3, 6-4 Friday to move into the semifinals of the Moselle Open.

Muller will next face 2005 champion Ivan Ljubicic, who beat Dutch qualifier Igor Sijsling 6-4, 6-3.

Jo-Wilfried Tsonga also advanced to the last four by rallying past Nicolas Mahut 4-6, 6-3, 7-5 in an all-French encounter to next play third-seeded Alexandr Dolgopolov of Ukraine, who was leading 6-3, 1-0 when Xavier Malisse of Belgium retired.

The 49th-ranked Muller was at his shot-making best in the first set, hitting 19 winners to only five for Gasquet.

Muller cracked three aces in a row to win the opening set. In the second set, he broke at 1-1 and then saved five break points to clinch victory when Gasquet sent a backhand return long.

In the first quarterfinal, Ljubicic fired 13 aces, including one on match point. The fourth-seeded Croatian took the first set on a double-fault from Sijsling, who was playing his first quarterfinal on the main tour.

Ljubicic then broke serve to lead 4-2 in the next set.

Tsonga put Mahut under pressure at 5-5 in the final set, hitting two return winners and a forehand volley to earn three break chances. He converted the first with a half-volley that landed on the line to serve for the match.

The top-seeded Tsonga sealed the win by slamming an ace clocked at 214 kilometers per hour.

Tsonga lost the first set after dropping serve in the fifth game. He fought back in the second, capitalizing on two forehand errors from Mahut to lead 4-2.