Last week's Rotterdam runner-up Juan round winner, while second-seeded American Mardy Fish was a shocking loser Thursday at the Open 13 tennis event.

Making his ATP World Tour debut, 20-year-old French qualifier Albano Olivetti stunned the world No. 8 Fish 6-3, 3-6, 6-3 in 1 hour, 48 minutes. The 388th- ranked Olivetti piled up nine double faults, but also crushed 21 aces en route to the French-crowd-pleasing upset.

Meanwhile, the fourth-seeded former U.S. Open champion del Potro was tied with Nikolay Davydenko, 6-7 (6-8), 6-4, when the former world No. 3 Russian retired after two sets due to a foot injury. The 6-foot-6 Argentine del Potro smacked 16 aces before moving on.

The French faithful were treated to a pair of wins on Day 4, as fifth-seeded Richard Gasquet popped 10 aces in whipping Russian Igor Kunitsyn 6-3, 6-2 in 72 minutes, and Michael Llodra fired up 19 aces in taking out sixth-seeded Ukrainian Alexandr Dolgopolov 6-4, 5-7, 7-6 (7-5) on the indoor hardcourts at Palais des Sports. Gasquet will appear in his fourth quarterfinal of 2012 and battle the formidable del Potro on Friday.

Llodra titled here in 2010 and was the Marseille runner-up in 2009. He'll face Olivetti in an all-French affair on Friday.

Another Friday quarterfinal will pit top-seeded Jo-Wilfried Tsonga against fellow Frenchman Edouard Roger-Vasselin. Tsonga captured the Marseille title in 2009.

Also on Day 5, third-seeded Serb Janko Tipsarevic will battle seventh-seeded Croat Ivan Ljubicic, who was the Marseille runner-up back in 2005.

The newest Marseille champ will collect $120,000.