A hot and bothered Novak Djokovic has bounded into yet another Australian Open semi-final with a hard-fought win over Taylor Fritz amid farcical scheduling at Melbourne Park.

The pesky American 12th seed made life difficult for 36-year-old Djokovic on Tuesday afternoon in their sweltering quarter-final clash on Rod Laver Arena.

The 10-time Australian Open champion was agitated at times during the three-hour-and-45-minute battle, before reaching his 48th grand slam semi-final with a 7-6 (7-3) 4-6 6-2 6-3 victory.

Watch every Australian Open match ad-free, live & on demand with centre court in 4K Ultra-HD on the home of Grand Slam tennis, Stan Sport.

“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 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.”

Djokovic is now just two wins away from clinching an unprecedented 25th grand slam that will surpass Margaret Court’s magic mark of 24 which has stood since 1973.

The victory sets him up for a semi-final encounter against either Italian fourth seed Jannik Sinner or Russian No.5 seed Andrey Rublev, who play later on Tuesday.

The match ended just before 8.30pm local time, delaying the night-session quarter-final double header which was due to begin at 7pm.

Belarusian world No.2 Aryna Sabalenka and 2021 French Open winner Barbora Krejcikova are scheduled to lead off the session, before Sinner and Rublev take to the court.

Equalling Roger Federer’s record of 58 grand slam quarter-final appearances, Djokovic was denied his favoured prime-time night slot on Rod Laver Arena for a second successive match.

He boasted an unblemished 8-0 record against Fritz across their previous tour meetings, including a most recent straight-sets win at last year’s US Open.

The first ball of the match-up was not struck until 4.43pm local time after American Coco Gauff’s marathon win over Ukrainian Marta Kostyuk.

Djokovic immediately turned on the blowtorch but the American withstood the initial test, fending off two break points in a 24-point first game that spanned 16 minutes.

So sweltering was the 31C heat that the 10-time Open champion uncharacteristically donned a cap at the sun-facing end and repeatedly turned to ice packs to cool down.

At one change of ends, Djokovic screamed at his box to get their attention after rifling through his supplies.

Fritz, a first-time quarter-finalist in Melbourne, found his bearings and bought up two sets points at 6-5 but the GOAT showed his superior metal to force a tiebreak.

After a poor start to the tiebreak, Fritz’s first-set fate was effectively sealed with a vintage passing shot from a fired-up Djokovic who blew a kiss to Australian Nick Kyrgios in the commentary box.

Fritz made amends by breaking Djokovic in the first game of the second set after the Serb inexplicably served three double faults and never got it back.

The king of Melbourne Park had failed to convert any of his first 15 break point chances before breaking through early in the third and going on to break another three times.

Gauff wins through

Fourth seed Coco Gauff may have gone from the hunter to the hunted but didn’t fall prey to a courageous Marta Kostyuk to book a spot in the Australian Open semis.

The reigning US Open champion extended her grand slam-winning streak to a dozen matches with a rollercoaster 7-6 (8-6) 6-7 (3-7) 6-2 victory in Tuesday’s first women’s quarter-final at Melbourne Park.

She had to scrap for more than three hours in scorching heat as 21-year-old Kostyuk overcame painful blisters to threaten a huge boilover.

The Ukrainian underdog eventually yielded as Gauff progressed to a semi-final on Thursday against either second-seeded defending champion Aryna Sabalenka or Czech ninth seed Barbora Krejcikova.

The American conceded to serving up a sub-par performance but was satisfied in taking a page out of her coach Brad Gilbert’s book to win ugly.

“Today was definitely a C game,” said the 19-year-old after becoming the first teenage woman since Maria Sharapova to win 12 consecutive grand slam matches this century.

“I didn’t play my best tennis but really proud that I was able to get through today’s match. Hopefully I got the bad match out of the way and I can play even better.”

The pair racked up a whopping 107 unforced errors between them across 246 points, compared to just 56 winners.

Kostyuk’s initial barrage caught Gauff off guard before she recovered from 1-5 down to claim the first set.

“I knew going in, playing her, it was (going to be) a tough match,” said Gauff.

“She’s pretty athletic, and we kind of play similar. Today she was just more offensive, which I wish I was taking the offense from the beginning.”

Last September, Gauff became the first teenager since 23-time grand slam champion Serena Williams in 1999 to win the US Open title. 

Playing her final major as a teen, the Florida native said she’s noticed a change in her opponents’ demeanour after bagging her first slam.

“There is definitely a change in just the energy,” Gauff said when asked about going from hunter to hunted. 

“You do feel like you’re the one to beat and I feel like people step on court and they … play their best games because there’s no pressure.

“I definitely feel a little change. But also, at the same time, not really, because when I was young nobody wanted to lose to a 15-year-old, so I felt people played really hard too.

“There’s a quote, ‘it’s … easier to get to the top but harder to stay there’. The goal is to stay here as long as possible and keep going upwards.”

Gauff has won all two of her previous slam semi-finals, easily accounting for Italian Martina Trevisan at the 2022 French Open and Czech Karolina Muchova at Flushing Meadows last year.

She was unaware of her flawless last-four record at the majors so far but wasn’t shying away from it.

“It does give me confidence knowing that at least in that stage of a grand slam that my nerves are usually settled,” said Gauff.

“Hopefully I can go out there and be settled.”