The Australian let out an uncharacteristically loud roar of delight on Monday, overjoyed at reaching the last-eight for the first time while providing an unhappy ending to the fairytale run of French Open champion Barbora Krejcikova.

"Being in the quarter, I'm happy, I'm excited," smiled Barty after her 7-5 6-3 victory over the Czech, who'd seemingly forgotten how to lose a tennis match until Barty's skill reacquainted her with the sinking feeling on No.1 Court.

"It's another stepping stone for me, another first, I suppose. It's going to be a new scenario, one that I'm going to look forward to and enjoy no matter what," said the world No.1.

"Certainly happy with the way things are going. It's a stepping stone to what is kind of one of my biggest dreams. We just keep chipping away..."

It's turning into an impressive sculpture. The top seed ended Krejcikova's amazing 15-match unbeaten streak on the tournament's famous 'Manic Monday', when all 16 last-16 matches are played, with a performance that blossomed in authority as the match progressed.

It set up a last-eight meeting on Tuesday with compatriot Ajla Tomljanovic, Australia's No.2, who moved on after British teenage wildcard Emma Raducanu retired injured. Tomljanovic was 6-3 3-0 ahead.

She will find it tough against the world No.1 in this mood, after Barty found a way, after a demanding one hour 35 minutes, of unravelling the puzzle of the tricky Krejcikova, whose odyssey has seen her defeat all-comers on the clay courts of Strasbourg and Roland Garros.

But the grass always felt like Barty's domain - even away from the Centre Court which had become home for her in the first week - as she surpassed her Wimbledon run of 2019, when she reached the fourth round.

For even while still not being at her absolute best - she still produced more unforced errors (24) than winners (21) - Barty was able to outmanoeuvre Krejcikova and dismantle the assured all-court game of the No.17 seed with her own enviable variety of shot.

"An incredibly tough match. Honestly, she's been one of the very toughest players to beat," Barty said.

Tomljanovic was 6-3 3-0 ahead in their last-16 clash on Monday when Emma Raducanu, having called for the trainer, had to go off court to be treated for a problem with breathlessness that appeared to have cropped up at the start of the second set.

Raducanu, 18-year-old Briton, was not well enough to return to the court - the most unfortunate end to what had been the most professional of performances from the Australian No.2 to beat Britain's new teenage show court darling.

"I am actually shocked because Emma must be hurt if she came to the decision to retire," Tomljanovic told the No.1 court crowd.

"I am really sorry for her, I wish we could have finished it. I am wishing her all the best.

"I thought I found my groove although Emma was hurt and not at her best, which kind of explains it."

The whole of the home nation had been cheering on the wildcard Raducanu, ranked 338th in the world, who captured everyone's imagination through her run to the last-16, but the seasoned world No.75 Tomljanovic quite ruined the script.

Tomljanovic was not about to miss out on the most important victory of a meandering career on No.1 Court as the 28-year-old Brisbane player celebrated reaching the last-eight of a slam for the first time at the 27th time of asking.

Australian Associated Press