Melbourne (AFP) - Iga Swiatek came from a set down to make her maiden Australian Open semi-final Wednesday by battling past gutsy veteran Kaia Kanepi to set up a last-four clash with Danielle Collins.

Just 20, the consistent Polish seventh seed proved too resilient, ending the unseeded Estonian’s surprise Melbourne Park run 4-6, 7-6 (⁷⁄₂), 6-3 on Rod Laver Arena in a exhausting 3hr 1min.

She will play Collins on Thursday for a place in the final after the American 27th seed ground down Alize Cornet 7-5, 6-1 to match her Australian Open exploits from 2019.

Swiatek is in the second week for a sixth consecutive Grand Slam since her 2020 French Open triumph, but it the first time she has made the last four away from the Paris clay.

Ranked nine, she is now projected to move to fourth in the world and could go as high as three if she wins the title.

“I had so many break points (nine) in the first set that I felt like I missed my chances,” said Swiatek.

“I was pretty annoyed and I should have been focused on the next point. And that’s what I did in the second set exactly that.

“They are easy things to do but they are working. I felt like she was playing so fast that I couldn’t be tight. so I had to finish my forehands basically. That was enough.”.

Remarkably, 115th-ranked Kanepi turned professional in 1999, two years before Swiatek was born.

But despite the 16-year age gap the Estonian showed plenty of fight as she looked to make a first Grand Slam semi-final since playing her first in 2006.

They both held serve to 2-2 in the opening set but Swiatek was the more dangerous, nailing a high percentage of returns to create three break points without converting any.

With Swiatek winning more than 80 percent of her first service points, Kanepi needed to capitalise on the second serve.

The Estonian bided her time and pounced in game seven, slamming a forehand return to go 4-3 ahead.

Swiatek saved four set points in a huge ninth game and incredibly another four as Kanepi served for the set before she finally got over the line after 64 minutes.

The Polish star’s day worsened when she was broken first up in the second set, but she wasn’t ready to give in. She broke straight back then held and with Kanepi seemingly wilting, struck again to take a 3-1 lead.

But a ninth Swiatek double fault helped Kanepi break back and the set went to a tiebreaker, where the Pole regrouped to dominate.

They exchanged early breaks in the deciding set before Swiatek broke again for 3-2. She looked destined to sweep home but Kanepi made life difficult before a late break ensured the Pole was victorious.