Ana Ivanovic will meet Kim Clijsters in the Cincinnati Open semi-finals after progressing along with Russian teenager Anastasia Pavlyuchenkova and Maria Sharapova on Friday.
Serbian former world number one Ivanovic, looking in-form and confident, comfortably defeated Uzbek qualifier Akgul Amanmuradova 6-1, 6-3 to reach her second semi-final of the year.
The unseeded Ivanovic, who reached the last four in the Italian Open in Rome, won 22 of 24 first service points and looked composed throughout the game.
"I think it has to do with confidence. You know, once you feel confident that you've got a game out there and you've got tools, you can fall back on those.
"At the moment, I feel if my forehand isn't working, I can fall back on something else; if that's not working I can fall back on my movement and just trying to get to the balls and somehow get them back," she said.
Clijsters, who is preparing to defend her US Open crown later this month, was pushed all the way by 11th seeded Italian Flavia Pennetta before clinching a 7-6, 6-4 victory.
Clijsters, who launched her comeback at this event last year, made 39 unforced errors and conceded she was not at her best.
"The errors are there because I still don't feel that everything is going naturally they way that I would want it to go. I'm really just trying to work for each point," she said.
Sharapova had little to worry about in her defeat of France's Marion Bartoli, with the Russian producing a blistering service game, winning 29 of 30 first serve points and smashing nine aces in her 6-1, 6-4 victory.
The three-times Grand Slam winner will face a tough semi-final after Pavlyuchenkova displayed the temperament of a veteran to beat Belgian 12th seed Yanina Wickmayer 7-5, 3-6, 6-1.
She was 5-1 down in the first set but saved three set points to rally back superbly, winning six successive games.
Wickmayer, who later said she had felt weak in her legs and drained in the midday heat, called for the courtside doctor when she was 6-5 down.
There was an almost identical start to the second with Wickmayer going 5-0 up before Pavlyuchenkova again battled back though the Belgian forced it into a decider.
Buoyed by her spirited resilience, the 19-year-old Russian powered through the third to take her place in the last four.
The teenager never doubted her ability to come back against Wickmayer, even when trailing 5-1 in the opening set.
"I guess I have always been like that since I was a little girl," she said.