Top seed Rafael Nadal's grass-court warm-up ended with defeat by France's Nicolas Mahut in the quarter-finals of the Artois Championships.
Mahut is 104 places below Nadal in the world rankings
As rain repeatedly interrupted play again at Queen's Club, Mahut was one of several players forced to play twice.
He first beat fifth seed Ivan Ljubicic 7-6 (7-3) 6-3 before returning to see off Nadal 7-5 7-6 (7-0).
He will play compatriot Arnaud Clement in Saturday's semi-finals, while Andy Roddick will take on Dmitry Tursunov.
"It's the best day in my tennis life," Mahut told BBC Sport. "It's amazing."
Roddick remains on course for a fourth title at Queen's after enjoying the easiest day of anyone but he was still below his best in beating Croatian wildcard Marin Cilic 6-4 7-6 (7-5).
To get to the quarter-final on grass is not so bad for me
"I played spotty today," said Roddick. "I was a little bit sloppy with some of the errors.
"If I want to get through two more matches and try to win this tournament again, I'll have to do better than that."
The American will take on seventh seed Tursunov in the last four after the Russian caused another shock with a 6-3 6-7 (5-7) 6-4 defeat of third seed Fernando Gonzalez.
"The rain delays are difficult," said Tursunov. "It's something about being in Britain! I just tried to keep my patience during the breaks and not coming out playing too many shots."
Chilean Gonzalez led 4-2 in the final set but lost the lead and his temper, smashing his racquet on the way and receiving a warning from the umpire.
The day had started well for Nadal, who needed just five minutes to wrap up his rain-delayed match against Max Mirnyi 7-6 (7-3) 6-3.
Fernando Gonzalez let his temper get the better of him
But the Spaniard was always under pressure against in-form Mahut - a former Wimbledon junior champion - and his challenge faded as he failed to register a point in the second-set tie-break.
"It was tough, I really didn't play very well," said Nadal. "I tried my best with the best attitude, but I only had one or two chances.
"He served very well but I'm happy with my tournament. It is difficult to play every day and to get to the quarter-final on grass is not so bad for me."
And the Spaniard will take the chance to head home to Mallorca before returning for Wimbledon.
"I will now go home," said Nadal. "I want to play some golf, watch the end of the football season, and have some fun with my friends.
"I need to put the tennis racket far away from myself for a few days. The positive thing is that I will have time at home, but the negative thing is that I won't have the chance to play the semi-final or the final here at Queen's."
Mahut goes on to face Clement, who had an equally impressive day as he saw off fourth seed Novak Djokovic 2-6 6-3 6-4 and then former finalist Ivo Karlovic 7-5 6-4.
Britain's Jamie Murray and American Eric Butorac went out of the doubles with a 7-6 (7-5) 6-4 loss to third seeds Paul Hanley and Kevin Ullyett in the quarter-finals.