British teenager Mika Stojsavljevic beat former Australian Open champion Sofia Kenin to claim her first WTA Tour main-draw win – despite only having an hour’s notice that she would be playing.

The 17-year-old lost in qualifying for the Hong Kong Open but entered the main draw as a lucky loser.

World number 411 Stojsavljevic came through a close deciding set to beat the American 6-3 4-6 6-4.

“I only knew an hour before I was going to be playing. I kind of just went out and swung today,” Stojsavljevic said.

“I know she’s a Grand Slam champion and it was never going to be an easy match, but I believed in myself and it worked out.”

Kenin, 27, has had a torrid time since winning the Melbourne title in 2020 but is still ranked 224 places above the Briton.

Stojsavljevic hit six winners to her opponent’s zero and saved three of the eight break points she faced.

It is a second big win of the year for Stojsavljevic, who stunned then world number 56 Talia Gibson at Billie Jean King Cup qualifying in April.

Stojsavljevic started playing tennis aged seven at Ealing Lawn Tennis Club in north-west London after watching her brother practise.

In 2024, she became the first Briton in 15 years to win the US Open junior title.

She reached a high of fifth in the junior world rankings and turned professional in 2025.

Earlier this year, she reached the quarter-finals of the WTA 125 event in Birmingham – the tier that sits below the main Tour.

Stojsavljevic will face world number 67 Zeynep Sonmez in the second round in Hong Kong.