Novak Djokovic and Coco Gauff have both been made to toil for semi-final places at the Australian Open, but organisers have been spared a ridiculously late finish, as Aryna Sabalenka and Jannik Sinner roared through the night session.
Two epic battles in the afternoon meant defending women's champion Sabalenka did not walk onto Rod Laver Arena until well after 9pm, but the Belarusian made light of Czech Barbora Krejcikova, winning 6-2 6-3 to ease pressure on the schedule.
Fourth seed Sinner then beat fifth seed Andrey Rublev 6-4 7-6(5) 6-3 just before 1:30am to set up a mouthwatering clash with Djokovic and leave a shattered Rublev picking over a 10th defeat in 10 Grand Slam quarter-finals.
Holder Djokovic was expected to breeze past Taylor Fritz, after coming into the contest with an 8-0 win-loss record over the 12th-seeded American, but he endured a stern test that lasted four hours to prevail 7-6(3) 4-6 6-2 6-3.
"This match was not an enjoyable match for me at all," said Djokovic. "Of course, I'm proud to overcome the kind of challenge and obstacles, and I'm pleased to win, but it wasn't enjoyable at all.
"It was really... a lot of suffering in every aspect. You have days like that, where you just have to accept it, face the circumstances and try to make the most out of it."
Fritz - at 26, a decade younger than his opponent - made the Serb sweat in a tight first set that the American dropped in a tiebreak, before drawing level in the contest on a steamy day, when both players looked physically drained at times.
"I played a really high level for the first two sets and they were physically tough," said Fritz. "It was like two-and-a-half hours by the time we finished the two sets.
"I need to get to the point where I can do that for five hours."
Djokovic has had some tough moments on his way to reaching his 48th Grand Slam, but is now two wins away from a record-extending 11th Melbourne Park title and 25th Grand Slam to eclipse the record he shares with Margaret Court.
Invariably, he finds a solution and Gauff was forced to do the same against Ukraine's Marta Kostyuk, admitting she had to win "ugly", as she triumphed 7-6(6) 6-7(3) 6-2 in a scrappy match lasting a little over three hours.
"Yes, it was a fight," said US Open champion Gauff, who had to battle back from 5-1 down in the opening set. "I think today was definitely a 'C' game.
"Hopefully, I got the bad match out of the way."
She will certainly have to against reigning champion Sabalenka, who had far too much power for 2021 French Open champion Krejcikova in a match lasting only 71 minutes.
"I think it was a really great match today," said Sabalenka, who lost to Gauff in the US Open final. "I played really great tennis, and I really hope I can just keep playing that way or even better."
With the day session taking so long, Sabalenka says she was asked whether she wanted to switch her semi-final to Margaret Court arena, rather than play it on Rod Laver.
"Yes, they asked our opinions, if we want to be moved, but Novak won that set 6-2 and it still was quite early, so we decided to wait for this match."
She certainly made up for any lost time and Sinner also looked determined to avoid the sort of 4am finish that might have damaged his hopes of landing his first Grand Slam.
After cruising through the opening set in 38 minutes, he found himself under fire in the second, as Rublev upped the power and carved out a succession of break point chances - none of which he could convert.
Rublev's big chance came as he moved 5-1 ahead in the second-set tiebreak, but again, Sinner dug his way out of a hole and once he had reeled off six successive points to grab a two-set lead, he was never going to falter.
He now turns his focus to world No.1 Djokovic, whom he beat twice at the back end of last year.
"It's going to be tough, but the only thing I can control is that I'll fight 100 percent for every ball and see what happens," said Rublev, 22.
Reuters
