SYDNEY, Australia - Ashleigh Barty played scintillating tennis to return to the Sydney International semifinals for the second year in a row, winning against No.10 seed Elise Mertens in straight sets, 6-3, 6-3.

Barty extended her winning streak to six matches in a row, dating back to her career’s biggest title at the WTA Elite Trophy in Zhuhai and continuing in Sydney, where she opened her week with back-to-back wins over two French Open champions, taking down Jelena Ostapenko and then World No.1 Simona Halep to reach the quarterfinals.

Read more: Barty ices World No.1 Halep for career victory in Sydney

“I’m always thinking about my game, and how I can improve and get better,” Barty said after the match. “But for me it’s more about how I come out and play.

“I always try to play my game, and not get sucked in into how they [other players] want me to play. It’s important for me to serve well and look for forehands and try and be dominant from that first shot.”

Barty made a nervy start in Sydney against Mertens, with a handful of loose errors putting her opponent ahead at 1-2. But the Australian No.1 responded emphatically, reeling off the next four games in a row to get ahead 5-2. She kept Mertens under pressure with her heavy pace, batting off a break-back point and serving out the set comfortably.

There was a bit more tug of war in the second set, where Barty carried the momentum and created two break chances in the very first game. The Aussie finally struck first, and weathered a rash of three consecutive breaks of serve to lead 4-3. She rattled off the last three games in a row to seal the match after an hour and 17 minutes on court.

“It was important to try and get ahead in games today,” Barty assessed in her post-match press conference. “Elise is a great front-runner. I knew I had to try and take control of those first two or three points in games to give myself a chance. One sloppy game from me on serve in the second set was probably the only blemish.”

Up next in the semifinals, Barty awaits the winner between No.7 seed Kiki Bertens and the tricky Yulia Putintseva. Putintseva roared into the quarterfinals with a 3-6, 7-6(4), 6-0 statement win over Sloane Stephens, while Bertens advanced after receiving a walkover from Garbine Muguruza (gastrointestinal illness).

“Bertens has had an unbelievable year, she really has, and Yulia had an amazing win last night over Sloane, so I’m sure that will be a hell of a battle,” Barty said. “Hopefully the rain stays away!”