Unranked Australian teenager Olivia Gadecki has completed Sofia Kenin's miserable summer with a stunning win over the fallen Australian Open champion at Melbourne Park.
The 18-year-old wildcard from the Gold Coast sent the American packing from the Phillip Island Trophy WTA event with a 2-6 7-6 (7-4) 6-4 second-round victory on Sunday.
"After that first set I was still trying to find my feet, find my way in the match," Gadecki said.
"But then something kind of clicked at 3-2.
"I was like, 'you know what, I have nothing to lose here, I'm just going to go out here and have a good swing' and then yeah, it carried on to the third set.
"... all I know is that I'm not ranked, and I just beat No. 4 in the world, which is crazy."
Kenin's Open title defence ended in tears three days ago with a shock second-round loss to veteran Kaia Kanepi and now the world No.4 must digest one of the worst defeats of her career.
Carrying $US235,800 ($302,500) in prize money and precious rankings points, the Phillip Island Trophy offered early-round Open losers a chance to atone.
But for top-seeded Kenin - who was among three grand slam champions in the draw - it only provided more despair.
The 22-year-old had also lost in the quarter-finals of the Yarra Valley Classic, meaning the WTA's 2020 player of the year only won three matches in three events in Australia.
For Gadecki, it's clearly the biggest win of her career.
Her first victory in the professional ranks only came last month at Australian Open qualifying in Dubai.
That result earned her a wildcard for this week's tournament.
She vindicated her entry with a first-round win over fellow Australian Destanee Aiava on Saturday before turning the tournament upside down with Sunday's triumph.
Gadecki trained with world No.1 Ash Barty during pre-season and had her fellow Queenslander watching on from the stands.
"I've been very fortunate enough to have Ash training in Brisbane and she gave me the opportunity to do her preseason and also my preseason with her," Gadecki said.
"So I wouldn't have been able to do what I did today without all her help and her time and effort."
Gadecki's victory earned her a last-16 crack at either Swede Rebecca Peterson or Belgian Greet Minnen.
"This win means that I'm not far, and I can really do this," she said.
"I feel like I can really make this dream of mine a reality."
Australian Associated Press