Aslan Karatsev of Russia in action during the quarterfinals of the Australian Open on Tuesday at Melbourne Park.

MELBOURNE, Feb 16: As well as she played at the start of her Australian Open quarterfinal, Serena Williams suddenly was struggling early in the second set.

After one mistake against No. 2 seed Simona Halep – who won the last time they played each other – Williams pointed at her racket strings and made a sour face, as if to make clear it wasn’t truly her own fault. After another, Williams looked up at her guest box with palms up and asked, “What is happening?”

That dismay did not last long. Williams claimed the last five games and beat Halep 6-3, 6-3 on Tuesday to return to the final four at Melbourne Park for the first time since she won the tournament in 2017.

Seeking a record-tying 24th Grand Slam title, Williams set up a showdown against No. 3 Naomi Osaka, who will carry a 19-match winning streak into Thursday’s semifinals.

This will be their fourth career matchup – all on hard courts – and Osaka leads 2-1, the most memorable encounter, of course, coming in the final of the 2018 US Open.

Williams got into an argument with the chair umpire after her coach was caught trying to relay a signal – that’s not allowed in Grand Slam play. Osaka’s victory, which earned her first major title, closed with thousands of fans filling Arthur Ashe Stadium with boos and both of the athletes were in tears during the trophy ceremony.

There were no spectators on Tuesday in Rod Laver Arena, because they have been banned from the tournament during a five-day government lockdown in response to a local rise in COVID-19 cases (the applause and other crowd noise TV viewers are hearing is being added to the broadcast feed and isn’t actually happening in the stadium).

That loss to Osaka in Flushing Meadows is part of an 0-4 record for Williams in Grand Slam finals since her last championship. Another one of those defeats came against Halep at Wimbledon in 2019.

In the men’s quarterfinals in Melbourne, 114th-ranked qualifier Aslan Karatsev of Russia became the first man in the professional era to get to the semifinals in his first Grand Slam appearance, defeating No. 18 seed Grigor Dimitrov 2-6, 6-4, 6-1, 6-2.

“Of course, it’s (an) unbelievable feeling … first time playing main draw, first time (making) semis, it’s incredible,” said Karatsev, securing victory in two hours and 32 minutes to guarantee a minimum prize money of at least $US662,000.

“It was really tough from the beginning for me to hold the nerves … I tried to find a way and then in the third he felt the back,” said the Russian, who had already earned bragging rights as the lowest-ranked player to reach the final eight in Melbourne in 30 years.

In the first women’s quarterfinal, Osaka overpowered 71st-ranked Hsieh Su-wei of Taiwan 6-2, 6-2, helped by serves that reached 122 mph (196 kph). She delivered seven aces, claimed 23 of 25 first-serve points and wound up with 24 total winners to just 14 unforced errors. – AP

Djokovic enters semifinal

Melbourne, Feb 16: Novak Djokovic dropped the opening set against Alexander Zverev, one of the young guys trying to shove aside Djokovic and the rest of the Big Three. Djokovic trailed 3-0 in the third. And 3-0 in the fourth, too, eventually even facing a set point.

But Djokovic pulled himself together and pulled out the victory, reaching his ninth semifinal at Melbourne Park by eliminating No. 5 seed Zverev 6-7 (6), 6-2, 6-4, 7-6 (6) on Tuesday night. – AP