Ash Barty reached her sixth semi-final of the year after winning the battle of grand slam champions against Barbora Krejcikova at the Western & Southern Open.
World number one and top seed Barty – the Wimbledon titleholder – dispatched French Open champion Krejcikova in straight sets in Cincinnati on Friday.
Another slam champion awaits Barty in the form of Angelique Kerber, while wildcard Jil Teichmann continued her fairytale run with victory over Olympic gold medallist Belinda Bencic.
Coffee the tonic for in-form Barty
Australian star Barty was too good for Krejcikova, winning 6-2 6-4 at the WTA 1000 tournament.
Barty had to battle from a break down in the second set against the fast-rising Krejcikova, who has shot up from 65th in the world to a career high of number 10 this year.
After extending her season record to 38-7, Barty talked about the importance of drinking coffee in the morning.
"I travel with a French press and an AeroPress, just to have two options. Usually every tournament we go to, one of us has a cafe that we have been to before, so I have got a little section of all my local cafes from the tournaments, so we try and get out to those if we can," she said.
"This year, some places we haven't been able to; some places we have. It's been nice to get some sort of a mixture, but I'm pretty simple. I'm just a black coffee cup in the morning, and then I'm set."
Three-time major champion Kerber is next up after she was 6-4 3-3 ahead before Petra Kvitova retired hurt due to a stomach problem.
Teichmann takes down another star
Unheralded Swiss and world number 76 Teichmann claimed another scalp, this time upstaging countrywoman Bencic 6-3 6-2 in the quarter-finals.
Teichmann stunned world number two Naomi Osaka en route to the quarters and maintained her giant-slaying form in Cincinnati, where 10th seed Bencic became the latest victim.
"We hugged before the match; we hugged after the match," Teichmann said of the Bencic meeting. "We know that once we step on court it's business, it's just another player I have to deal with, and she had the same mindset. At the beginning it's obviously a bit special, but once we're in it, we just look at the game, not looking at the opponent, or at least I do that way."
Teichmann will take on fifth seed Karolina Pliskova, who advanced to her second successive WTA 1000 semi-final after Paula Badosa retired down 7-5 2-0.