Americans Madison Keys, Alison Riske and Danielle Collins advanced to the quarter-finals of the Brisbane Open after all three recorded straight sets victories in Wednesday's singles matches.
Riske became the first player to book her spot in the quarter-finals with a 6-3 6-4 win over the Czech Republic's Barbora Strycova.
The 29-year-old American, who lost to Strycova in their previous two meetings, broke her Czech opponent five times in the 93-minute encounter to set up a potential clash with second seed Karolina Pliskova.
"It was a good win for me," Riske told reporters. "(Strycova is) going to be a tough out every time you play her. She makes a lot of balls, she's in every point and she's battling until the end."
Eighth seed Keys was pushed in the first set by hometown favourite and former U.S. Open champion Samantha Stosur but eventually prevailed 7-5 6-3 in 78 minutes.
Keys fired 10 aces and 24 winners past the Australian wildcard to beat Stosur for the first time in four attempts and set up an all-American quarter-final clash with Collins, who beat Yulia Putintseva 6-1 6-0.
Collins saved all five break points she faced and broke her Kazakh opponent six times to wrap up the match in just 58 minutes, winning 80% of her second serve points.
Australian top seed and world number one Ash Barty, who received a bye into the last-16, plays her first match on Thursday against American qualifier Jennifer Brady while Pliskova takes on Ajla Tomljanovic.
(Reporting by Rohith Nair in Bengaluru; Editing by Lincoln Feast.)
