Defending Australian Open champion Naomi Osaka, two-time Wimbledon champion Petra Kvitova and Madison Keys won quarterfinal matches Friday at the Brisbane International.
Osaka beat Kiki Bertens 6-3, 3-6, 6-3, Kvitova defeated qualifier Jennifer Brady 6-4, 6-2 and Keys beat fellow American Danielle Collins 6-4, 6-1. Brady was coming off wins over Maria Sharapova in the first round and top-ranked Ash Barty in the second.
Keys, a 2017 U.S. Open finalist, reached the semifinals in Brisbane for the first time in four attempts.
"Happy to get a lot of matches in and feel like a lot of what I was working on during off-season is kind of immediately clicking," Keys said. "There's still some things that I want to do a little bit better, but it's definitely a great starting point for the year."
In a later quarterfinal, Brisbane defending champion Karolina Pliskova played Alison Riske.