British number one Johanna Konta suffered a shock defeat by world number 123 Bernarda Pera in the second round of the Australian Open.
The American won 6-4 7-5 to claim only her second win at Grand Slam level.
Ninth seed Konta had reached the quarter-finals and semi-finals on her past two visits to Melbourne Park.
She saved four match points on a hot and blustery afternoon but framed a smash on the fifth to give 23-year-old Pera the biggest win of her career.
Pera goes on to face Barbora Strycova in the third round after the Czech 20th seed beat Spain’s Lara Arruabarrena 6-3 6-4.
Konta, 26, has now won just three of 11 matches since reaching the Wimbledon semi-finals in July.
Pera lost in qualifying and only made it into the main draw of a Slam for the first time as a lucky loser, after another player withdrew through injury.
The Croatia-born American has taken full advantage, deservedly knocking out ninth seed Konta with relentless attacking off her returns and forehand.
“I was ready to leave on Monday,” said Pera. “When I got in I was so excited and to win two rounds is amazing.”
Konta could not cope with the pace and depth coming at her, while her own serve failed to make much impact, and she finished without hitting a single ace.
Despite landing 70% of her first serves, she would end the match having won just 54% of those points, while 14 winners illustrated her struggle to hit through Pera.
An overhead that was completely missed, followed soon after by a mishit smash on match point, summed up the way her game had unravelled.
It was clear from the outset that Pera was going to provide a far sterner test than her ranking suggested, with a break point going begging in the first game.
A “come on!” from Konta just for holding serve at 3-3 told of the pressure that Pera was applying, and two brilliant returns gave the American the only break of the first set.
The conditions were playing their part, with Konta missing successive backhands from mid-court as the wind swirled, but two double-faults in a row suggested the occasion might finally be getting to Pera as she slipped 2-0 behind in the second set.
That theory was debunked within minutes as Pera tore into another Konta service game, breaking straight back after the Briton telegraphed a poor drop shot.
Konta was under huge pressure now, battling well to save five break points before Pera made the seemingly decisive breakthrough at 4-3.
There was a final flash of resistance from Konta.
She staved off three match points and then broke to level at 5-5, but a desperate service game followed and she would end up flat on her back on the baseline as Pera broke for a fourth time.
With her game creaking, Konta’s spirit remained willing at least.
A fourth match point was seen off before Pera finally clinched the win of her life, when the Briton could only frame a smash into the stands on match point number five.