Former French Open champion Jelena Ostapenko was dumped out of the Prudential Hong Kong Tennis Open Monday – by a player ranked 299 places below her.

The Latvian world number 18 crashed out in three sets against outsider Kristina Kucova of Slovakia – who before Monday had not had a WTA main draw win over a year – in the first round of the ongoing WTA Hong Kong event, which runs from October 6 to 14 at Victoria Park Tennis Stadium.

"It's a great feeling to play on such a big court against a great player," Kucova said after the match.

"After struggling so long with my knee and my health, it's a good pump and push to keep going."

In terms of their play against Chinese players this year, Kucova played Zhang Shuai during the women's singles first round at 2018 French Open in May. And Ostapenko had a match against Wang Qiang during the China Open earlier this month.

Third seed Ostapenko scraped through the first set 7-5 before losing her way in the second with repeated netted-ground strokes and Kucova's backhand tipping the scales in the Slovak's favor.

The match ended when a shot by Kucova was called in even though it appeared to land well beyond the baseline. An angry Ostapenko, out of challenges, then faced a double match point and quickly succumbed to go down 7-5, 3-6, 2-6.

"In tennis sometimes one ball can decide the whole match. That ball was quite far out – I was surprised the chair umpire didn't call it," Ostapenko said.

"But unfortunately I had run out of challenges and couldn't do anything."

Ostapenko, only 21, was looking to recover from a poor China Open performance hampered by a wrist injury, but instead endured a miserable evening in Hong Kong.

She said her 28-year-old opponent had played like she had "nothing to lose".

"Today she was playing at a very high level but of course it was not the best match and I made a lot of unforced errors."

(Top image: Jelena Ostapenko of Latvia (L) receives treatment on her arm during her play at the China Open in Beijing, October 2, 2018. /VCG Photo)