World number two Rafael Nadal led an exodus of seeds at Queen's Club on Friday when swirling winds threw Wimbledon preparations off course for several players.
Third seed Fernando Gonzalez, number four Novak Djokovic and fifth seed Ivan Ljubicic also lost, with French players doing most of the damage.
Andy Roddick, however, survived and will be favourite to claim his fourth title here in five years after overcoming dank conditions to reach the semi-finals with a 6-4 7-6 win over Croatian wildcard Marin Cilic.
Top seed Nadal was undone 7-5 7-6 thanks to the superior court coverage of an inspired French opponent ranked 106th in the world.
Nicolas Mahut earlier accounted for Ljubicic in a rain-delayed third-round match before handing out similar treatment to the French Open champion.
Slipping and sliding behind the baseline, Nadal squandered break point opportunities at 5-5 in the second set. Mahut then took the tiebreak 7-0, falling to his knees as he sealed a famous win.
"It's the best day in my tennis life," said Mahut, the 2000 junior champion at Wimbledon.
"I beat Ljubicic this morning and Rafa now. To beat two top-10 players in the same day is amazing," he told reporters.
Nadal said: "I didn't play very well."
Arnaud Clement completed a good day for France, winning back-to-back matches to set up a semi with his friend Mahut.
Serbian fourth seed Djokovic, a semi-finalist at Roland Garros, went down 2-6 6-3 6-4 to Clement.
The 14th-seeded Frenchman was back on court less than four hours later to fell towering Croatian Ivo Karlovic 7-5 6-4.
Third seed Gonzalez looked to be heading towards a showdown with Roddick until he succumbed 6-3 6-7 6-4 to Dmitry Tursunov in a match twice interrupted by showers.
Struggling to control Tursunov's powerful groundstrokes, the 26-year-old Chilean smashed his racket to a mangled wreck when the Russian rallied from 4-2 down to level 4-4 in the decider.
Gonzalez was given a code violation and surrendered his title prospects two games later.
Roddick rallied from 4-2 down in the second set to end the promising run of Cilic.
"It was a little bit sloppy at times. If I'm going to get through two matches to win this tournament, I'm going to have to play better than that," said the American second seed.