Defending Australian Open champions Novak Djokovic and Aryna Sabalenka are through to the semifinal at Melbourne Park after securing wins on Tuesday.
Djokovic was tested by American 12th seed Taylor Fritz over four sets, while Sabalenka was clinical in her straight-sets victory over Czech ninth seed Barbora Krejcikova.
The defending champions will now face Italian Jannik Sinner and American star Coco Gauff respectively, in their semifinals.
Djokovic, who has won the Australian Open all 10 times he has previously passed the quarterfinal stage, was agitated at times during the three-hour-and-45-minute battle, before reaching his 48th grand slam semifinal with a 7-6(7-3), 4-6, 6-2, 6-3 victory.
"I suffered a lot in the first couple of sets (and) also due to his high-quality tennis," Djokovic said.
"He was serving well, he was staying close to the line, he was really suffocating me from the back of the court.
"It was extremely hot while the sun was still out there — physically very draining (and) emotionally as well."
The king of Melbourne Park could not convert any of his first 15 break point chances but broke his duck early in the third set before doing it another three times.
"Conversion of break points was really poor," Djokovic said of his four-for-21 success rate.
"But, at the end of the day, I managed to break him when it mattered in the third and the fourth.
"I upped my game probably midway through the third set all the way to the end. I served extremely well … I had even more aces (20 to 16) than he did, which is a surprise stat."
Djokovic has drawn within two wins of clinching an unprecedented 25th grand slam that would lift him past Margaret Court's magic mark of 24, which has stood since 1973.
Meanwhile, Sabalenka demolished Krejcikova in a one-sided contest.
In a match that started more than two hours, the world number two put on another clinic at Rod Laver Arena to win 6-2, 6-3 in 71 minutes.
Sabalenka has dropped just 16 games and won every set across her five matches.
The 25-year-old did drop a service game late in the second set but still cruised to a 12th-straight victory at Melbourne Park.
"It was a really great match and I played really great tennis and I hope I can just keep playing that way or even better," Sabalenka said.
"I've been working so hard last year and this pre-season, I think it's all about hard work on the practice court so you're ready for the matches."
The Belarusian is aiming to become the first woman since countrywoman Victoria Azarenka in 2012 and 2013 to win consecutive Australian Open titles.
Follow the action in our live blog, get the full scores with our ScoreCentre, and tune in to our radio coverage.
Sports content to make you think... or allow you not to. A newsletter delivered each Friday.
AAP/ABC
That is where we will leave the blog today
The first day of the quarterfinals are done and dusted.
Coco Gauff, Aryna Sabalenka, Novak Djokovic and Jannik Sinner are through to the semifinals.
Who joins them from the other half of the draws? We find out tomorrow (later today).
We will see you then as the live coverage from Melbourne Park continues on the ABC live blog.
Goodnight.
The winning moment for Jannik Sinner
Jannik Sinner defeats Andrey Rublev in straight-sets
Outstanding from the Italian.
He played the perfect game against his Russian opponent.
Sinner is yet to drop a set at this year's Australian Open.
Heartbreak for Rublev.
This is his 10th grand slam quarterfinal, and he is yet to win one.
He will rue losing the second set tie breaker after being up 5-1.
Sinner leads third set 5-3, serving for the match
Jannik Sinner can end this now and book his maiden Australian Open semifinal.
Sinner gets the break in the third set
Jannik Sinner was outstanding in the sixth game.
He breaks Andrey Rublev, with a gorgeous forehand winner.
He leads the third set 4-2, with the serve.
Is he on his way to a straight-sets win?
Sinner again holds serve when Rublev has chances
Rublev is asking questions of Sinner's serve, but the Russian cannot get the break he needs.
Eight times he has had break point and he has not been able to convert.
Sinner faced two break points in the third game of this third set, again again he was able to hold.
He leads this set 2-1, Rublev to serve the fourth game.
This was the point which changed the tie breaker
Sinner was down 1-5.
He won the first of what would be six consecutive points, but it was the second point in that stretch which felt like the turning point.
A 24-shot rally which ended with the most lovely winner.
Sinner steals the second set tie breaker
Jannik Sinner has come from the brink of defeat to win the tie breaker.
Sinner was 1-5 down. Andrey Rublev was in complete control and looked like he couldn't miss.
And Sinner then wins six consecutive points to take it 7-5.
Rublev doesn't know what hit him. The set was his, and three minutes later he is sitting in his chair, screaming at his coaching box.
Sinner holds serve. Second set is going to a tie breaker
Massive moment in this match.
Jannik Sinner can go two sets up.
Andrey Rublev can get it back to all square.
Rublev holds serve, Sinner serving to send us to a tie breaker
Andrey Rublev was flawless with the serve.
Pressure is on Jannik Sinner, he needs to hold this serve to send the second set to a tie breaker.
Note: I said in the previous post that Sinner was serving to send this set into a tie breaker, when the set was 5-4. Counting appears to be a weak point of mine
Rublev saves break points, runs to the loo
Andrey Rublev has saved break points to hold serve.
He then sprinted off the court to a nearby loo.
He leads 5-4. Jannik Sinner is serving keep the set alive.
Sinner grabbing his abdomen in the second set
Something is bothering the Italian.
Jannik Sinner will be hoping this issue is resolved soon.
The clock strikes midnight as Rublev leads 4-3 in the second, on serve
Happy Wednesday everyone.
The clock has passed midnight and tomorrow is now today.
Rublev has looked improved in the second set, and has the lead 4-3. The set is on serve.
In case you are wondering, the men's semifinals will be held on Friday.
So the winner will get more rest than they would have in the earlier rounds.
Sinner appears to be holding his abdomen
Jannik Sinner appears to be massaging his abdomen, a possible concern for the Italian's camp.
Sinner was serving the sixth game, where he survived a break point to hold, when the massaging became noticeable.
It is 3-3 and on serve in the second set.
Andrey Rublev, who had missed a few break points already, is serving.
Why are we playing so late?
I fell asleep last time I asked, why are they playing tennis so late! It’s crazy! What am I missing here?
- HP
I suppose it is based on scheduling.
The first two matches on Rod Laver Arena were lengthy.
Coco Gauff took the court at 1pm AEDT. Is that too late?
Maybe it was today.
But the ABC live blog will be here until the end.
Bring on more tennis.
Sinner survives two break points
Andrey Rublev has missed a golden opportunity to take the advantage in the second set.
He had Jannik Sinner's serve under pressure, twice had a break point, but could not come up with the goods.
The second miss was the one that hurt the most, with his shot just missing the line wide.
Jannik Sinner wins first set 6-4 over Andrey Rublev
The Italians take the upper hand in this quarterfinal.
He had the one break to take the set 6-4.
The set was decided in the fourth and fifth games.
Sinner serving, Rublev had two break points but was unable to convert.
Sinner then broke Rublev's serve to love.
That ultimately was the difference between the pair.
Sinner serving for the set
The Italian has been good on his serve and he has the only break of the match.
Up 5-4, he will now serve for the opening set.
Sinner gets the first break over Rublev
Andrey Rublev was wayward with his shots on serve and it has cost him.
Jannik Sinner was able to break the Russian's serve to love, getting the first break of the match.
He will now serve, up 3-2.