Images from Tuesday's action at the Australian Open.
Serena Williams came through a huge test of her Australian Open title credentials to reach the last four at Melbourne Park for the ninth time with a 6-3, 6-3 victory over Simona Halep in a high quality quarter-final on Tuesday.
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 Naomi 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.
Eventually, however, 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.
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 US Open final between the two.
"She's a great player on the court and an inspirational person off it," said Williams.
"I feel this is a great opportunity for me just to do my best in the first Grand Slam of the year."
Djokovic edges out Zverev to reach semi-final
Reigning champion Novak Djokovic overcame some dips in form to beat Alexander Zverev 6-7(6), 6-2, 6-4, 7-6(6) and book his place in the Australian Open semi-finals.
The Serbian world number one hit back strongly after losing a tight opening set on a tiebreak but trailed in both the third and fourth sets before turning them around.
Germany’s Zverev will rue allowing Djokovic back from 4-1 down in the third set and he was also up 3-0 in the fourth.
Djokovic again wore tape on his abdominal area, a legacy of the injury picked up in his third-round win over Taylor Fritz. But it did not appear to bother him as he reached his 39th Grand Slam semi-final, where he will face an unlikely opponent in Russian qualifier Aslan Karatsev.
The 23-year-old Zverev began in confident fashion and secured the first break of the match but failed to convert a set point on Djokovic’s serve when leading 5-3.
He wavered on his own serve at 5-4 though, and Djokovic took the set into a tiebreak, only for some uncharacteristic errors to allow Zverev to sneak a 59-minute set.
Djokovic needed only 29 minutes to win the second set but his level dropped at the start of the third, and he destroyed a racket in anger as he slipped 4-1 behind.
Zverev was 0-30 ahead on Djokovic’s serve in the next game but Djokovic found another gear, winning 20 of the next 24 points to move one set from victory.
Another momentum shift saw Zverev take a 3-0 lead in the fourth set and have three points to move 4-0 ahead, but Djokovic dug in to haul himself back into contention.
Zverev threatened to take the match into a decider but Djokovic saved a set point at 5-6 with an ace and a powerful first serve brought up match point in the day’s second tiebreak.
Djokovic netted a backhand but forced a volley error from Zverev to earn another chance, this time on his own serve, and he wrapped up the match with his 23rd ace.
Qualifier Karatsev stuns Dimitrov to enter semis
Aslan Karatsev continued his sensational run at the Australian Open into the semi-finals when he stunned Grigor Dimitrov 2-6, 6-4, 6-1, 6-2 to become the fifth qualifier to reach the last four of a men’s Grand Slam in the open era.
The world number 114 regrouped after an error-filled opening set to add the 18th seed to his list of upset victims at Melbourne Park and set up a clash with Novak Djokovic or Alexander Zverev for a place in the final.
Dimitrov looked shell-shocked as the Russian tightened up his game and pounded howitzer shots over the net -- faltering on serve and wandering around the Rod Laver Arena court listlessly in the 30 degree Celsius heat.
The 29-year-old Bulgarian took a medical time-out for treatment on his back after losing the third set but Karatsev would not be denied as he became the lowest-ranked player to reach a Grand Slam semi-final for two decades.
Osaka thrashes Hsieh to reach semis
The brute force of Naomi Osaka crushed the artistry of Hsieh Su-wei as the Japanese former champion charged into the Australian Open semi-finals with a 6-2, 6-2 win.
On a warm and muggy day at Rod Laver Arena, Osaka attacked Hsieh's weak serve with gusto and the Taiwanese giantkiller quickly wilted under the pressure of her Grand Slam quarter-final debut.
Osaka had a torrid time in her last Australian Open clash against Hsieh in 2019, needing to come back from a set and a break down on the way to claiming the championship.
So the Japanese third seed was thrilled with her form against the Taiwanese maverick in a 66-minute clinic.
"Yeah, definitely really happy," 23-year-old Osaka said on-court.
"Really happy with how I played today. Every time I play her it's a real battle and, despite the score, this was again a real battle today."
Osaka's reward will be a semi-final against either Serena Williams or Simona Halep, the pair having a rematch of the 2019 Wimbledon final in the evening session at Rod Laver Arena.
"I always watch Serena's matches, anyway," said Osaka, who has never failed to win a Grand Slam after making the quarter-finals.
"Definitely going to be real fun."
Hsieh, 35, bowed out after a stellar tournament, having become the oldest women's player to debut in a Grand Slam quarter-final in the professional era.
The improbable angles conjured by her double-handed, double-sided game had Osaka in some trouble early, but Hsieh was unable to convert any of the three break points she raised in the opening games of the first set.
Osaka quashed the first of them in the opening game with an ace down the 'T' and smashed Hsieh's defences with a blazing backhand down the line to break to 3-1.
After holding on grimly through a 14-point game to hold serve, Osaka raised the pressure when Hsieh served to stay in the set at 5-2 and sealed it when the Taiwanese slapped a limp backhand wide.
Hsieh was soon in a tailspin, pounding a backhand well over the line to be broken to 2-0, emboldening Osaka to race to the finish.
Having suffered some famous wobbles in the past, there was no hint of frustration from Osaka when Hsieh saved two match points.
She bided her time to claim the win on the third when an overwhelmed Hsieh floated a sliced backhand long.