Serena Williams crushed world No.2 Simona Halep 6-3 6-3 to reach the last four at the Australian Open for a ninth time and set up a showdown with Naomi Osaka.
The 39-year-old went toe-to-toe with the Romanian second seed over 80 minutes on Rod Laver Arena before she was finally able to move to within two victories of a record-equalling 24th Grand Slam title.
Williams hit some ferocious forehands and moved around the court with a freedom that she has not enjoyed for a good while to set up a semi-final meeting against in-form Japanese third seed Osaka.
"I think this was the best match I have played at this tournament, for sure," Williams said after celebrating her win to the accompaniment of canned applause as Melbourne's coronavirus lockdown kept the fans away for a fourth day.
"I knew it had to be going up against the number two in the world. I had to be better and I was, so I'm excited."
If any match at this year's tournament deserved a crowd, it was this. There were nine breaks of serve as two great competitors punched and counter-punched over lengthy rallies.
Williams was always in front in the first set but needed to dig deep to wrestle back the momentum after Halep took a 3-1 lead in the second.
The match turned decisively when Williams broke for 4-3 after a 13-shot rally where she showed incredible athleticism to get to a couple of shots that would have defied most players.
Seven minutes later, she wrapped up the contest with a huge forehand, her 24th winner.
"My feeling after this match is that I was not that far (away) but she was stronger in the important moments," said Halep.
"I'm not that disappointed with myself."
Williams has not landed one of the game's major prizes since her seventh title at Melbourne Park in 2017, with Halep's victory in the 2019 Wimbledon final denying her one opportunity to match Margaret Court's record.
After gaining a measure of revenge for that defeat, Williams has the chance to avenge another when she plays Osaka, who won the 2018 U.S. Open final between the two.
"I feel this is a great opportunity for me just to do my best in the first Grand Slam of the year," she said.
Osaka sticking to the plan at Australian Open
Naomi Osaka has never lost a Grand Slam after making the quarter-finals and if all goes to plan at the Australian Open she will be savouring a fourth major triumph before her 24th birthday.
The Japanese third seed reached the semi-finals with a clinical 6-2 6-2 win over Hsieh Su-wei, two years after suffering a big scare in an emotional rollercoaster of a match against the Taiwanese maverick at the 2019 tournament.
Osaka said her dominance in the rematch showed how much better she had become at sticking to a plan rather than relying on her instincts.
"I would say for me today it was really important to have a plan just because she's an opponent that I'm not really sure what's going to happen," Osaka said of the mercurial Hsieh, who beat her at Miami in 2019.
"So just having something to structure myself and not get carried away with what she's going to do was definitely really important.
"I feel like being able to receive information is something that I've been learning, and it's something that I feel my experience over these past couple years has helped me.
"Because, I think a couple years ago I probably wouldn't be able to understand what I was supposed to do that well here.
"But definitely I feel like I'm getting better at being able to stick to a plan. I know my attention isn't that great all the time, but yeah."
Osaka, who will play Serena Williams in the semi-finals, could face world number one and home hero Ash Barty in a blockbuster decider if the Australian also survives.
Crowds are expected to return to the tournament on Thursday after a five-day lockdown due to a COVID-19 outbreak, and Osaka said she hoped Barty could have fans present for her bid to end Australia's 43-year wait for a home champion.
"Even for me, I've played the finals before with no crowd," said Osaka, who won her second U.S. Open title last year without fans at Flushing Meadows due to biosecurity protocols.
"It's definitely memorable. But I'm sure for her, if she reaches the finals and there's no crowd, it would be memorable but kind of in a sad way.
"I'm sure she would want a crowd. For me, I would want a crowd, too, even if they don't cheer for me. That's just the way life is. It's just more fun."
-Reuters