Jo-WIlfried Tsonga beats Bernard Tomic at Marseille Open 13

Sixth-seeded Gilles Simon upset defending champion Juan Martin del Potro of Agentina 6-4, 6-3 Friday to set up an Open 13 semifinal against countryman

Jo-Wilfried Tsonga is the top-ranked Frenchman, just ahead of Richard Gasquet :: KOEN SUYK/EPA

Sixth-seeded Gilles Simon upset defending champion Juan Martin del Potro of Agentina 6-4, 6-3 Friday to set up an Open 13 semifinal against countryman Jo-Wilfried Tsonga, who earlier saved five match points in a 4-6, 6-3, 7-6 (10) win against Australia's Bernard Tomic.

Meanwhile, top-seeded Tomas Berdych of the Czech Republic reached the last four after beating seventh-seeded Jerzy Janowicz of Poland 6-3, 6-7 (0), 6-3. Berdych did not face a single break point and took Janowicz's serve twice.

The third-seeded Tsonga hit 19 aces against Tomic to reach the semifinals of the tournament for the third time and stay on course to repeat his 2009 win. In a match that lasted over two hours, Tomic showed great resilience as the Australian saved eight of nine break-points he faced, but couldn't capitalize on his chances in the decider.

Dmitry Tursunov of Russia also advanced by beating Gilles Muller of Luxembourg 7-6 (7), 1-6, 7-5 in his quarterfinal.

Tursunov, a semifinalist at the tournament two years ago, withstood 27 aces from Muller and a second-set thrashing where he dropped serve three times to set up a semi against Berdych.

"Playing in qualifying for the third tournament this year, I really didn't expect this," Tursunov said. "I wasn't really looking that far ahead and I think that kind of helped me, I was just trying to play one match at a time."