Polish qualifier Jerzy Janowicz continued his brilliant run at the Paris Masters on Friday while fourth seed David Ferrer knocked out local favourite Jo-Wilfried Tsonga.
Spaniard Ferrer ruthlessly dismissed 2008 winner Tsonga 6-2 7-5 to set up a semi-final with unseeded Frenchman Michael Llodra who put out American Sam Querrey 7-6 6-3.
Serb Janko Tipsarevic, who had on Thursday claimed the last spot for next week's World Tour Finals in London, withdrew when trailing 3-6 6-1 4-1 against Janowicz and having called the trainer on to the court one game earlier.
Organisers said he had been suffering with fatigue from the end of the first set.
While the crowd booed Tipsarevic, world number 69 Janowicz celebrated becoming the first qualifier to progress to the last four since 2004.
"I just felt like today on the court, especially during the second and third set, it was unbelievable and I felt like I could do everything that I wanted," the Pole told a news conference.
"After the first set I relaxed a little bit and I did something magical. I played like I could put every single ball in."
The unseeded Janowicz, who eliminated world number three Andy Murray on Thursday, showed signs of nerves at the start and dropped his serve in the second game.
CUNNING DROP SHOTS
However, his mix of raw power from the baseline and cunning drop shots eventually wore down Tipsarevic who simply ran out of ideas.
The 21-year-old Janowicz next faces Frenchman Gilles Simon who advanced with a 6-4 6-4 win over Czech fifth seed Tomas Berdych.
The unseeded Simon, who reached the quarter-finals after Japanese Kei Nishikori withdrew due to an ankle injury, was too good for Berdych in front of his home crowd.
Simon trailed 4-1 in the second set but fought back to win five games in a row, wrapping up the contest with an ace on his second match point.
Tsonga, who also secured a berth in the World Tour Finals on Thursday, was never in the hunt against a focused Ferrer, the highest-ranked player left in the draw after Murray and world number two Novak Djokovic had been dumped out.
Frenchman Tsonga heads to London having failed to beat any player from the world's top eight all year.
"It's complicated to play at Bercy just before the Tour Finals but I wanted to win the tournament once more," he said. "As soon as tomorrow I'll be on court in London to practice."
Ferrer, who did not face a single break point, raced through the first set and although the sixth-seeded Frenchman increased the pressure in the second, Tsonga was too sloppy to seriously trouble his opponent.
Tsonga was 0-40 down in the 12th game. He saved two match points with decent first serves but then sent a routine forehand wide on the third.