Cincinnati - France's Julien Benneteau won 12 of the last 15 games to stun Australian Open champion Stan Wawrinka 1-6, 6-1, 6-2 in Cincinnati on Friday and reach the first Masters semi-final of his career.
Benneteau, ranked 41st in the world, fired nine aces and broke the third-seeded Swiss four times in the 80-minute contest.
He was quickly followed into the final four of the last major US Open tune-up by fifth-seeded Canadian Milos Raonic, who crushed 15th-seeded Italian Fabio Fognini 6-1, 6-0 in just 57 minutes.
Raonic awaits the winner of the night's marquee men's match-up -- second-seeded Roger Federer taking on eighth-seeded Andy Murray.
Murray, seeking his first title since his emotional Wimbledon triumph of 2013, holds a slim 11-10 edge over 17-time Grand Slam champion Federer in their career head-to-head.
But it was Federer who won their most recent meeting, in the quarter-finals of the Australian Open.
"I played a really good match against him in Australia," Federer said, although he knew that Murray was still recovering from back surgery.
Murray goes into the match with the confidence of having saved two match points en route to a third-round win over big-serving American John Isner.
"I know I'm in for a tough one," Federer said.
Benneteau next faces sixth-seeded David Ferrer.
After sweeping through the first set in 27 minutes, Wawrinka could find no answer to Benneteau who broke for a 2-0 lead in the second set and rolled from there.
He finished off the victory with an ace on the first of two match points.
"It's my best result in Masters 1000," said Benneteau. "They are very, very difficult tournaments. It's the top 45 players in the world.
"You don't have a lot of opportunities to make a very big result in Masters 1000. But the tournament is not done, and I still have a lot to do."
Benneteau is making his ninth appearance in Cincinnati, a key tune-up event for the US Open, the final Grand Slam of the year that starts on August 25.
His previous best showing was a quarter-final in 2009.In women's action at the combined ATP and WTA event, top-seeded Serena Williams cruised into the semi-finals with a 6-1, 6-3 win over Jelena Jankovic.
"She's beaten me several times, so I knew today I just had to be focused and do the best I could," said Williams, a 17-time Grand Slam champion who has never lifted the trophy in Cincinnati.
"She played some great points. I was just trying to not make many errors, stay focused and do the best that I could."
Williams will next face former world number one Caroline Wozniacki.
Second-seeded Simona Halep of Romania will get a chance to avenge her Roland Garros final loss to Maria Sharapova when she takes on the fifth-seeded Russian for a semi-final berth.
Sharapova has beaten Halep in all four of their meetings, although both of their matches this year have gone three sets, first in Madrid and again in the gripping French Open final that saw Sharapova claim her fifth major crown.
The winner of that
match will play either ninth-seeded Ana Ivanovic or Ukrainian teenager
Elina Svitolina, who vanquished Wimbledon champion Petra Kvitova in the
Julien Benneteau (FRA) bt Stan Wawrinka (SUI x3) 1-6, 6-1, 6-2
Milos Raonic (CAN x5) bt Fabio Fognini (ITA x15) 6-1, 6-0
David Ferrer (ESP x6) bt Tommy Robredo (ESP x16) 6-4, 3-6, 6-3
Roger Federer (SUI x2) bt Andy Murray (GBR x8) 6-3, 7-5
Serena Williams (USA x1) bt Jelena Jankovic (SRB x8) 6-1, 6-3
Caroline Wozniacki (DEN x12) bt Agnieszka Radwanska (POL x4) 6-4, 7-6 (7/5)
Maria Sharapova (RUS x5) bt Simona Halep (ROM x2) 3-6, 6-4, 6-4
Ana Ivanovic (SRB x9) bt Elina Svitolina (UKR) 6-2, 6-3