Unseeded French veteran Alize Cornet upset Simona Halep at the Australian Open in brutal heat Monday to make her first Grand Slam quarter-final on her 63rd attempt.

Both players struggled as the temperatures hit 33 Celsius (91 Fahrenheit) on Rod Laver Arena, but it was the 32-year-old who prevailed 6-4, 3-6, 6-4 in a gruelling 2hr 33min.

She will now play 27th-seeded Danielle Collins for a place in the semis after the American outlasted Elise Mertens 4-6, 6-4, 6-4 in a near three-hour epic.

The breakthrough has been a long time coming for Cornet, who made her Grand Slam debut at the French Open in 2005 but had never been past the fourth round before.

Thailand’s Tamarine Tanasugarn previously held the record for most appearances before reaching a quarter-final at this level, achieving the feat on her 45th try at Wimbledon in 2008.

“It feels amazing. That battle I had with Simona today and the heat. After 30 minutes we were both dying and we kept going for two-and-a-half hours,” said Cornet, who upset world number three Garbine Muguruza in round two.

“Simona is such a fighter and an example for me. To be able to go to my first quarter-final is a dream come true.”

They traded breaks in the opening set, with Cornet striking first, before the 14th-seeded Romanian levelled.

With the ice-towels out to keep them cool, they pounded away from the baseline and it was Cornet who came out on top to break two-time Grand Slam winner Halep and move 5-3 clear.

She was unable to close out the set as Halep powered a backhand volley out of her reach to break back, but Cornet once more broke the Romanian to seal it in 48 minutes.

But it took it out of her. Cornet had an ice bag on her head and was drinking as much fluid as she could at the changeover, and her hand appeared to be shaking.

She returned to loop a forehand long and lose her opening serve in set two, but with both players clearly struggling she then fared better to reel off three games in a row.

Halep seemed the more distressed, constantly bending over to catch her breath, but somehow persevered to break again and take a gruelling set after Cornet told the umpire of the heat: “It’s insane, it’s inhuman”.

The Romanian worked a break point at 3-2 in the final set but failed to convert and tossed her racquet away in disgust.

Instead it was Cornet who struck to move a break up at 4-3 as Halep netted a backhand with the Frenchwoman dropping to her knees in exhaustion three games later after clinching victory.

Collins wins an epic

Fired-up American Collins stayed on track to match her 2019 Melbourne Park heroics as she battled through an epic against Elise Mertens to make the Australian Open quarter-finals on Monday.

The 27th seed outlasted 19th seeded Mertens 4-6, 6-4, 6-4 in a 2hr 51min marathon in sweltering heat on Rod Laver Arena.

“It was really tough for me, I played a long match as well the other day so I had to make a lot of technical adjustments to be able to get myself moving around,” said Collins. “That was a big challenge.”

Collins stayed on track to match her 2019 Melbourne Park heroics. AFP

She is the third American woman to make the last eight, with Madison Keys and Jessica Pegula also through.

Collins was an Australian Open semi-finalist three years ago, but she has failed to match that effort since.

However, she clinched her maiden WTA Tour titles in San Jose and Palermo last year to rejuvenate her career after a tough start to 2021 when she needed surgery to remove a cyst.

She had a dream start, holding comfortably then breaking Mertens.

But the Belgium soon warmed to the task and pushed Collins hard on her next service game.

The American held on but Mertens worked her first break point and converted for 1-3 when Collins netted then threw her racquet to the ground in frustration.

Constantly berating herself, Collins began to wilt in the heat as Mertens stayed cool to win five games in a row and take an enthralling set.

But she composed herself at the changeover and raced to a 3-0 lead in the second set as she found her groove again and put constant pressure on the Mertens serve.

The rallies were again long and Collins prevailed to take it to a decider, where momentum shifted as they exchanged breaks before Mertens ended with a whimper, double-faulting on match point.