Keys banks on experience after surging into Australian Open semis

A resurgent Madison Keys said Tuesday she was a different person to the one that lost an Australian Open semi-final in 2015 and was now more prepared to go all the way.

Unseeded American Keys, ranked 51, pulled off another big upset to beat French Open champion and fourth seed Barbora Krejcikova 6-3, 6-2 on Rod Laver Arena and make the last four.

Her reward is a clash with either world number one Ashleigh Barty or fellow American and 21st seed Jessica Pegula for a place in the final.

The last time Keys got this far at Melbourne Park she was just 19 and came face-to-face with a dominant Serena Williams, the eventual champion.

"I would say it mostly feels different because I'm seven years older and it's not my first semi-final of a Slam," she said.

"I think I'm a little bit more prepared this time around than I was all those years ago.

"It's also a completely different situation, time and person, all of that. I think you take the experience that you have from those moments and you try to apply it, but you also know that it's going to be a completely different challenge."

That 2015 result helped propel her into the top 10. She went on to be a 2017 finalist at the US Open and made the last four at Roland Garros a year later.

But she endured a frustrating 2021, winning just 11 matches in the entire season, a mark she has now matched less than a month into the new year after winning a lead-up event in Adelaide.

The big-serving American came into the tournament as the WTA aces leader and signalled her return to form by beating 2020 champion Sofia Kenin and eighth seed Paula Badosa en route to the quarter-finals.

"It means a lot," said Keys. "Last year was really hard.

"I did everything that I could with my team to just reset in the off