'This is brutal': Australian Open rocked by 'awful' scenes

Tennis fans were left shattered for Barbora Krejcikova on Wednesday when the World No.4 wilted in the heat at the Australian Open.

The mercury went past 30 degrees in Melbourne on Wednesday, with the on-court temperature much higher during Krejcikova's quarter-final clash with Madison Keys.

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While Keys managed the heat to perfection and ran her opponent ragged, Krejcikova was clearly struggling.

After dropping the first set 6-3 and going down an early break in the second, the Czech rising star called for the trainer.

Krejcikova had her blood pressure checked and ice packs applied to her head and neck as she attempted to get some respite from the heat.

"You can see she's really struggling out there now," Jelena Dokic said in commentary for Channel Nine.

Unfortunately for Krejcikova she never righted the ship, with Keys prevailing 6-3 6-2 to advance to the semi-finals.

After an uncharacteristically cool start to the Australian Open last week, temperatures have been rising in recent days.

Alize Cornet and Simona Halep were both heavily affected by scorching temperatures on Tuesday as they played out an epic three-set battle in the middle of the day.

Keys had snapped Paula Badosa's unbeaten start to the year in the fourth round and set up a semi-final clash with the winner of Ash Barty's showdown with Jessica Pegula..

A former World No.7, Keys slumped to 81st in the rankings following a forgettable 2021 season dogged by injury and self-doubt.

But the 26-year-old is now riding a 10-match winning streak after launching her revival with a drought-breaking sixth career title at this month's Adelaide International 2.

Now she stands within two wins of an elusive grand slam crown many tipped the precocious talent would win years ago.

Keys first made the Open semi-finals aged just 20 back in 2015, before losing to great friend and fellow American Sloane Stephens in the US Open title match two years later.

Alize Cornet's extraordinary run to Aus Open quarters

Cornet burst into tears of relief and joy on Tuesday after finally advancing to the last eight at a grand slam at her 63rd attempt.

After dropping the first set on a stinking hot Monday afternoon in Melbourne, the 14th-seeded Halep looked to have righted the ship when she reeled off six straight games, having gone 3-1 behind in the second.

But the 32-year-old Cornet held her nerve as the temperature soared on Rod Laver Arena, clinching the 6-4 3-6 6-4 victory over Romania's two-time major winner on her third match point.

"It feels amazing," said Cornet.

"The battle I had with Simona today with this heat - after 30 minutes we were both dying on the court.

"We kept going for two and a half hours with all of our heart. Congratulations to Simona because I know she struggled a lot.

"I admire this player so much, she's such a fighter and an example for me.

"To beat her today to go to my first quarter-final is just a dream come true. I don't know what to say; it's just magic."

Cornet's opponent in the quarter-finals will be American Danielle Collins, who also needed three tight sets to overcome Belgian 16th seed Elise Mertens.

Cornet was playing in her 63rd major overall and her 60th in succession - just two shy of the all-time record held by retired Japanese player Ai Sugiyama.

Until now, her best performances at the grand slams had been five appearances in the fourth round, one of them at the Australian Open in 2009 when she blew two match points in a loss to Dinara Safina.

with AAP

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