Julien Benneteau upset the sluggish Roger Federer 6-3, 7-5 on Friday to reach the semifinals of the ABN AMRO World Tennis Tournament.
Defending champion Federer struggled with his serve and the timing of his ground shots throughout the match and Benneteau capitalized, punishing Federer on his second serves, for his second victory over the Swiss master.
"It is one of the biggest wins, for sure," the 39-ranked Frenchman said. "To play against Roger, Friday night, full house, it's a dream and I played like in a dream."
The loss ended the top-seeded Federer's bid to become the first player to win the Rotterdam tournament three times.
It also gave Benneteau a measure of revenge for last year's Wimbledon, when he blew a two-set lead to lose to Federer, and the London Olympics, where Federer beat him 6-2, 6-2.
The Frenchman set the tone by breaking Federer in the match's first game, pouncing on a Federer backhand that hit the net to power a backhand pass down the line for the game.
He looked to have stumbled in the fourth game when he served two double faults to allow Federer to break back, but Benneteau broke again in the seventh and ninth games to take the set.
He raced to a 4-1 lead in the second set before Federer again reeled off three straight games. The Swiss 17-time Grand Slam champion looked as if he was on his way back when he forced three break points at 5-5, but Benneteau grittily held service.
Summing up his sloppy play on the night, Federer served his fourth double fault to give Benneteau match point and the Frenchman immediately took it to win.
"I started bad, but fortunately got back into the game," Federer said. "But when you get broken as much as happened to me, you won't get the job done."
Earlier, Grigor Dimitrov rallied to overcome Marcos Baghdatis of Cyprus 6-7 (4), 7-6 (0), 6-3 to advance to the semifinals, where he will meet 2009 U.S. Open champion Juan Martin del Potro, who beat Jarkko Nieminen 6-3, 6-4.
Dimitrov broke Baghdatis' first service game of the final set to set up a win he celebrated by leaping over the net to hug his opponent.
"That was my last one percent of power," Dimitrov said. "Thank God I didn't injure myself."
The 21-year-old Dimitrov has been compared to a young Federer with a similar one-handed backhand, but he still doesn't possess the Swiss master's temperament. That was demonstrated by his smashing a racket into the court after Baghdatis broke his serve in the second set.
Del Potro also was frustrated against Nieminen, but the 6-foot-6 Argentine's serve saved him whenever he looked in trouble.
The second-seeded Del Potro served 10 aces, seven in the second set.
"It was a really difficult match," Del Potro said. "I played well, but I need to improve my game for the next round."
Dimitrov reached his first ATP final in January, losing to Andy Murray at the Brisbane International.
Gilles Simon advanced in the last quarterfinal after Martin Klizan retired with the score at 6-7 (6), 6-3, 3-0, meaning Simon will face Benneteau in an all-French semifinal.