Juan Martin Del Potro of Argentina defeated top-seeded Jo-Wilfried Tsonga of France 6-4, 6-7 (9), 6-3 in an Open 13 semifinal on Saturday.

Del Potro will face 2010 champion Michael Llodra of France, who defeated third-seeded Janko Tipsarevic of Serbia 6-4, 7-6 (10). Llodra saved six set points in the tiebreaker and converted his first match point when Tipsarevic hit a forehand wide.

Tsonga outslugged Del Potro with 26 aces to 15 but made too many unforced errors against the 2009 U.S. Open champion, who reached his second final in two weeks.

Del Potro broke for a 2-0 lead in the final set when Tsonga netted a backhand volley. He clinched the victory on a backhand from Tsonga that sailed wide.

"He was very solid and consistent behind the baseline," Tsonga said. "I couldn't find the solution. I fought until the end, but that was not enough."

Both players struggled early. Tsonga started with a double-fault and three unforced errors to drop the opening game. He broke back in the fourth game but made a forehand error to give Del Potro a 3-2 lead.

Del Potro slammed an ace to save a break point and whipped a forehand winner to erase another one at 4-3 before taking the first set with a service winner clocked at 129 mph.

Tsonga, who won this tournament in 2009, raised his game in the second set by hitting 26 winners to 16 for Del Potro.

Del Potro saved a set point at 5-4 to force a tiebreaker. Tsonga saved a match point at 8-7, then hit a forehand volley to convert his fifth set point and even the match.

"I look calm but inside ... I'm not really calm," Del Potro said. "When I missed shots like the first match point, I was on fire inside my body."

Del Potro lost to Roger Federer in the ABN Amro final last Sunday in Rotterdam, Netherlands.

The Argentine leads Llodra 2-0 in head-to-head matches.