Spanish young gun Carlos Alcaraz has been sent packing from the Australian Open with a quarter-final loss to German fourth seed Alexander Zverev in another late-night encounter on Rod Laver Arena.

Olympic champion Zverev put Alcaraz to the sword in the first set two sets and survived a fightback to battle into the semi-finals with a 6-1 6-3 6-7 (2-7) 6-4 win early on Thursday morning.

It marked the first victory of Zverev’s career over a top-five ranked opponent at grand slam level and equalled his best result at Melbourne Park.

The 2020 US Open runner-up will meet Russian world No.3 Daniil Medvedev on Friday for a place in Sunday’s final at Melbourne Park.

Zverev, 26, admitted to feeling some butterflies when coming within a game of knocking off world No.2 Alcaraz at 5-2 in the third set.

“We’re all human,” he said.

Alexander Zverev celebrates his stunning win. Photo: Getty

“It’s a great honour to play against guys like him and then when you’re so close to winning, obviously your brain starts going and it’s not always helpful.

“I fought back quite well in the fourth set, didn’t let go and then very happy to finish the match.”

The two-time grand slam champion swept past Zverev in straight sets at the same stage in last year’s US Open, with the German looking ragged after spending almost five hours and 39 minutes longer on court than Alcaraz.

The on-court time discrepancy (five hours and five minutes) was similar leading in to Wednesday’s quarter-final after Zverev survived two five-set epics through the first four rounds.

“I have a lot of blood under my toenails so that’s quite painful,” Zverev said when asked how his body was holding up.

“But, you know what, I would much rather feel the way I’m feeling right now with maybe a bit of pain here and there and be in the semi-finals than be at home right now watching this tournament.”

A defeated Carlos Alcaraz (right) and Alexander Zverev embrace. Photo: Getty

Battered body aside, it was Zverev who raced out of the blocks to break the 20-year-old Spaniard twice in the first six games.

Alcaraz had to wait until 2-3 in the second set to bring up break point chances but could not convert either and was promptly broken twice to fall in to a two-set hole.

He finally broke Zverev as the German served for the match at 5-3, smiling at the change of ends and eventually extending the match to a fourth following an inspired tiebreak.

Although the comeback fell short, Alcaraz was content with his run to his quarter-finals in Melbourne after previously never making it beyond the third round.

“I’m sad with my level today because I have been playing good tennis … but in general I leave the tournament happy,” he told reporters.

“Quarter-final of a grand slam is good. It’s not what I’m looking for but it’s not bad.”

‘Destroyed’ Medvedev makes  semi-final

Russian third seed Daniil Medvedev does not believe his taxing Australian Open campaign will affect him ahead of a third consecutive grand slam semi-final.

The two-time Open runner-up set up a final-four meeting with Germany’s Alexander Zverev by defeating Polish ninth seed Hubert Hurkacz 7-6 (7-4) 2-6 6-3 5-7 6-4 in a thrilling quarter-final on Wednesday.

After securing the win in three hours and 59 minutes with a tricky drop shot, Medvedev celebrated by blowing three kisses to his box, mainly directed at coach Gilles Cervara.

Medvedev’s second-round battle against Finland’s Emil Ruusuvuori earlier in this year’s tournament went to 3.39am after also going five sets.

After walking off the court, Medvedev wrote on a camera: “Just want to sleep now”.

“After every match, I’m in the locker room. I’m destroyed,” he said.

“One day off is probably enough to feel good the next day.

“So far, so good in the beginning of the matches, and that’s what matters.

“Then try to win, and then if you’re dead after, doesn’t matter because you have a day off.”

Daniil Medvedev in action against Hubert Hurkacz. Photo: Getty

The world No.3 is expecting his semi-final to be played as the night match on Friday, even though 10-time Open champion and world No.1 Novak Djokovic prefers the 7pm timeslot.

Djokovic and young Italian star Jannik Sinner won their quarter-finals on Tuesday, meaning they have an extra day off to recover than Medvedev.

Tight turnaround for Zheng

Chinese dark horse Zheng Qinwen faces a tight turnaround for her against-the-odds Australian Open semi-final stoush with Ukrainian qualifier Dayana Yastremska.

At 21, Zheng finds herself just two wins away from a remarkable maiden grand slam at Melbourne Park that would emulate the 2014 feat of fellow countrywoman and idol Li Na.

The 12th seed wrapped up the fourth and final spot in the last four of the women’s draw just before 10pm local time on Wednesday with a dogged 6-7 (4-7) 6-3 6-1 win over Russian Anna Kalinskaya.

The late finish left Zheng with less than 24 hours to recover for her showdown with Yastremska, the second of the women’s semi-finals scheduled for Rod Laver Arena on Thursday night.

Bound for the world’s top 10 regardless of result, the Chinese rising star indicated the short recovery window would not leave her much time for reflection.

“I don’t know if you can improve in less than 24 hours,” said Zheng.

“Basically I’ll be just trying to recovery and think about what I have to do for the next match … there is nothing I can change too much in 24 hours, right?

“So just keep simple and let’s go for it.”

Qinwen Zheng is two wins away from a maiden grand slam. Photo: Getty

About eight hours earlier, Yastremska became the first qualifier to make the semi-finals at Melbourne Park since 1978 following a straight-sets win over Czech teenager Linda Noskova.

She took the opportunity to scribble an emotional tribute on a courtside camera to soldiers back in her war-torn homeland after notching the most significant win of her career.

“I always try to write something for Ukraine, about Ukraine,” she said.

“It’s my mission here.”

Defending Australian Open champion Aryna Sabalenka will lock horns with reigning US Open winner and world No.4 Coco Gauff in the earlier blockbuster semi-final.

Bidding to become the first woman to win back-to-back Open crowns since fellow Belarusian Victoria Azarenka in 2012/13, Sabalenka is riding a 12-match winning streak at Melbourne Park.

Gauff has also won her past 12 grand slam matches, meaning something must give on Thursday night.

-AAP