Serena Williams out of Aussie Open after stunning quarter-final loss

Serena Williams was one point — just one — from quite a comeback victory in the Australian Open quarterfinals when she turned her left ankle.

Everything unraveled from there.

In a startling reversal and result, Williams wasted four match points along the way to dropping the last six games of a 6-4, 4-6, 7-5 loss to No. 7 seed Karolina Pliskova of the Czech Republic at Melbourne Park on Wednesday.

"I was almost in the locker room," Pliskova told the Rod Laver Arena crowd, "but now I'm standing here as the winner."

So instead of Williams moving closer to an eighth championship at the Australian Open and record-tying 24th Grand Slam title overall, it is Pliskova who will continue her pursuit of her first major trophy.

In the semifinals, Pliskova will face No. 4-seeded Naomi Osaka, who advanced by beating No. 6 Elina Svitolina 6-4, 6-1 earlier Wednesday. The other women's semifinal will be two-time Wimbledon champion Petra Kvitova against unseeded American Danielle Collins.

In the men's quarterfinals Wednesday, 2016 Wimbledon runner-up Milos Raonic met No. 28 Lucas Pouille, before 14-time major champion Novak Djokovic was scheduled to face 2014 U.S. Open finalist Kei Nishikori.

Williams' surprising departure scuttled what would have been a much-anticipated rematch against Osaka, who beat her in the chaotic U.S. Open final last September.

This defeat is the earliest in Australia for Williams since a fourth-round loss to Ana Ivanovic in 2014. Since then, she had won the tournament in 2015, lost in the final in 2016, and won again in 2017 while pregnant, before missing last year's edition a few months after the birth of her daughter.

Mistakes were mounting

The 37-year-old American's match against Pliskova was played under a stifling sun, with the temperature around 25 C, and Williams — coming off an intense three-set victory over No. 1 Simona Halep in the fourth round — often stepped into the patches of shade behind each baseline.

She did not start well, not well at all. Her mistakes were mounting and deficit was growing.

In the first set alone, Williams made more than twice as many unforced errors as her opponent, 11-5, a pattern that would continue throughout. By the end, the margin was 37-15.

Looking increasingly frustrated, Williams would yell at herself after mistakes or gesture as if to say, "That's NOT how I should be hitting the ball!" Add it all up, and Pliskova led by a set and a break at 3-2 in the second.

Only then did Williams seem to get going. From there, she immediately earned her first break point of the match and converted it to get to 3-all, beginning a run in which she claimed nine of 11 games.

"I was a little bit too passive," Pliskova said about that section of the match. "Obviously mentally down."

And then it all changed. Serving for the victory at 5-1, 40-30, Williams was called for a foot fault — reminiscent of an infamous such ruling at the U.S. Open a decade ago. During the ensuing point Wednesday, Williams twisted her left ankle and dumped a forehand into the net.

She grabbed at her foot afterward, and would go on to cede that game.

'I took my chances'

Not a big deal, right? She still had a sizable lead.

Except three more match points would follow, and Pliskova staved off each one.

Williams would again serve for the match at 5-3 — and again get broken. The owner of the most feared and respected serve in women's tennis was broken for a third time in a row at 5-all, and Pliskova was on her way.

"She got a little bit shaky in the end," Pliskova said. "So I took my chances. And I won."

Osaka will carry a 12-match Grand Slam winning streak into the semifinals.

The 21-year-old from Japan moved closer to a second consecutive major championship by parlaying her aggressive and powerful style into a 31-11 edge in winners against Svitolina.

"For me, right now, I just try to keep looking forward. So I'm not really satisfied. Like, I am happy that I'm here, but at the same time, I want to keep going," said Osaka, who never had been past the fourth round at the Australian Open. "There is more matches to win."

Later, Canada's Gabriela Dabrowski and mixed doubles partner Mate Pavic were bounced in the quarter-finals. The top-seeded pair fell 6-1, 4-6, 11-9 to Neal Skupski and Maria Jose Martinez Sanchez.