Melbourne (AFP) - A resurgent Danielle Collins said feeling herself again after difficult surgery, coupled with improved strength and stamina, helped power her into the last four of the Australian Open Wednesday.

The American 27th seed came through an intense clash 7-5, 6-1 in sweltering temperatures on Rod Laver Arena to shatter French veteran Alize Cornet’s dream of making a first Grand Slam semi-final.

She will face Poland’s Iga Swiatek for a place in the final after the seventh seed ousted Estonian veteran Kaia Kanepi in three tough sets.

Collins underwent surgery last year for endometriosis – where tissue similar to the lining of the womb starts to grow elsewhere – and said being pain-free had made a huge difference.

“I think I certainly feel a lot freer just not having to deal with the symptoms that I used to deal with, that not being a continuous issue that I’m dealing with on a daily basis,” she said.

“I think aside from surgery, I’ve gotten a lot physically stronger over the last couple of years. My strength and conditioning, my fitness, it’s been one of the most important areas of my training and focuses.

“That has transferred over to my tennis, the way that I’m able to play physically with my serving. My stamina on court has improved tremendously. I think just overall power and speed has improved.”

Defeat was bittersweet for the unseeded Cornet, who was in her first-ever Grand Slam quarter-final after 17 years of trying, but was unable to take it a step further.

“I have this little regret, but I gave everything I had on the court today which was less than the previous day, but that’s what I had,” said the Frenchwoman.

Collins, a terrific college player who didn’t turn professional until the age of 22, has been in fine form since recovering from her surgery last April and then tearing her abdomen at Roland Garros.

She returned to win her maiden WTA titles at San Jose and Palermo and has now matched her 2019 run at Melbourne Park, the only other time she has made a Slam semi-final.

With temperatures hitting 34 Celsius (93 Fahrenheit), both players held their opening serve as they sized each other up at their first meeting, with both renowned for their on-court intensity.

They probed for openings and the first break-point came on Cornet’s serve after Collins played a beautiful passing shot.

The Frenchwoman saved it and two more as the American pressed hard, and she got her reward with a backhand volley to move 3-1 in front.

Cornet clung on but Collins was giving her few opportunities, until game 10 when nerves struck as she served for the set.

She netted a backhand to allow Cornet to break back for 4-5, but the American kept her cool to earn three set points at 6-5, converting when Cornet whipped a looping forehand long.

Collins kept up the pressure in set two and after holding serve broke to go 2-0 clear with a blistering forehand, and Cornet’s head went down.

Broken again to slump 4-0 behind, there was no way back.

“To be able to get back to this level and be able to compete the way I have and be as physical as I have has been so rewarding,” said Collins.

“Especially playing against the girls I’ve been playing against the last couple of matches, really good competitors, really great athletes.”