(REUTERS, AFP) - Petra Kvitova overcame rain delays to beat defending champion Angelique Kerber 6-4, 6-1 on Thursday (Jan 10) and reach the Sydney International semi-finals.
In wet conditions at Ken Rosewall Arena, the Czech struggled to get going but took the final four games of the opening set, hitting 16 winners in the process.
German world No. 2 Kerber responded with a resolute defence to hold serve in the opening game of the second set and she earned three break points in the fourth, before a blistering backhand allowed Kvitova to take a decisive lead.
Fifth seed Kvitova will face Belarusian qualifier Aliaksandra Sasnovich, who beat Switzerland's Timea Bacsinszky 6-3, 6-3, in the semi-finals.
"It was the worth the wait to get back on court," she said.
"In the second time (off court) we played some games, some cards. I had a sandwich, I was listening to music and I was waiting (for) when the rain stopped."
Australia's Ashleigh Barty followed up her giant-killing wins over world No. 1 Simona Halep and former French Open champion Jelena Ostapenko by easily accounting for 10th seeded Belgian Elise Mertens 6-3, 6-3.
The 22-year-old is now on a six-match win streak, dating back to her career's biggest title at the WTA Elite Trophy in Zhuhai.
"Nice and solid today, I was pretty happy at the way I was able to come out and play," said Barty, ranked 15th in the world.
She will play seventh seed Kiki Bertens, who blasted past Yulia Putintseva 6-2, 6-2 for a place in the final.
Veteran Seppi derails Tsitsipas
In the men's draw, Andreas Seppi came back from a set down to knock out Greek top seed Stefanos Tsitsipas 4-6, 6-4, 6-4.
The 34-year-old Italian saved six of the seven break points against last year's Next Gen Finals winner Tsitsipas to seal his third semi-final appearance in Sydney.
"I always play my best tennis in Australia - I really enjoy playing here. It's great to be back here and in another semi-finals," said Seppi, who has progressed to the second week in four of his past six appearances at the Australian Open.
"It was very important to start well in the second set... I think was good to have early break so I could play a little more aggressive. It worked out in the end."
World No. 37 Seppi will next face third seed Diego Schwartzman, who overcame Japan's Yoshihito Nishioka 6-1, 3-6, 7-6 (7-1).
Seppi, 14 years older than his Greek opponent, has only won three ATP titles in his career, but called on all his experience as he battled back to win.
Australia has been a home away from home for the Italian in recent years. In a trio of round-of-16 appearances at the Australian Open, he pulled off upsets against Marin Cilic in 2013, Roger Federer in 2015 and Nick Kyrgios in 2017.
Defeat was a blow for world No. 15 Tsitsipas' preparations for the opening Grand Slam of the year in Melbourne next week.
He was one of the sport's most improved players last year, climbing from 91st after reaching finals in Barcelona and Toronto, losing both to Rafael Nadal, and was angling for the perfect start ahead of the Australian Open.
In other quarter-final action, fifth-seeded teenager Alex de Minaur continued his strong start to the season with a 7-6 (7-4), 6-3 victory over fellow Australian Jordan Thompson.