World number one Serena Williams stormed into the semi-finals with a 58-minute thrashing of Jelena Jankovic but men's third seed Stan Wawrinka was stunned by Frenchman Julien Benneteau at the Western & Southern Open on Friday.
Williams, bidding for her first title at the Cincinnati, Ohio hardcourt tournament, romped to a 6-1 6-3 victory over her Serbian opponent.
The unseeded Benneteau, meanwhile, overcame Swiss world number four Wawrinka 1-6 6-1 6-2 to reach his first Masters semi-final.
Williams needed just 25 minutes to claim the first set against Jankovic. She fell behind 2-1 in the second with an early break, but won five of the next six games, closing out the match with back-to-back aces.
"She's beaten me several times, so I knew today I just had to be focused and do the best I could," Williams told reporters after claiming her 10th win in 14 matches against Jankovic.
"It didn't seem fast," Williams said. "I was just trying my best. And she played some great points. I was just trying to not make many errors, stay focused and do the best that I could."
The top seed wound up with as many winners as unforced errors at 22-22 while the eighth-eeded Jankovic finished made five winners and 24 unforced errors.
Williams is bidding for a first title in six attempts at Cincinnati. The five previous failures are her second-most attempts at a WTA tournament without winning it. She has played the Sydney event six times without lifting the trophy.
Benneteau belted nine aces and broke serve four times in his 80-minute win as he earned his second victory over a top-10 opponent this year and became the first Frenchman in 14 years to advance to the Cincinnati semis.
Once world-ranked number 26, Benneteau lost the first set in 27 minutes. But he found a new head of steam and broke for a 2-0 lead in the second before claiming 12 of 15 games behind an impressive display of defence, winning 25 of 37 points and hitting 19 winners.
"It's my best result in a Masters 1000," Benneteau told reporters. "The Masters 1000 are very, very difficult tournaments . . . . It's top 45 players in the world on every tournament at this level. You don't have a lot of opportunities to make a very big result."
He was joined in the semi-finals at the US Open warm-up by Canadian fifth-seed Milos Raonic, who breezed to a 6-1 6-0 triumph over 15th seed Fabio Fognini of Italy in 57 minutes.