PARIS, France (AFP) — Aryna Sabalenka won a politically-charged French Open duel against Marta Kostyuk as jeers and boos rained down on the defeated Ukrainian who refused to shake hands with her Belarusian opponent.

World No. 2 and Australian Open champion Sabalenka swept 10 of the last 12 games to win 6-3, 6-2 as she kick-started her push to reach the second week in Paris for the first time.

Kostyuk honored her pledge not to shake hands with Sabalenka in protest at Russia's invasion of Ukraine. Belarus is a key military ally of Moscow.

The 20-year-old Kostyuk, who has been a vociferous critic of the decision to allow Russian and Belarusian players to keep competing on tour since the invasion of her country, questioned the crowd's motives in booing her stance.

"I want to see people react to it in 10 years when the war is over. I think they will not feel really nice about what they did," she said.

"I didn't expect it. People should be honestly embarrassed."

Kostyuk, ranked at 39 in the world, famously refused to shake hands with Sabalenka's Belarusian compatriot and former world No. 1 Victoria Azarenka at the US Open last year. She opted instead for a cursory touch of racquets at the net.

It's shocking how I played today.

"It was a very tough match, tough emotionally. I didn't know if the booing was against me but thank you so much for your support, it's really important," said Sabalenka who apologized for her exaggerated, theatrical bow to the Court Philippe Chatrier crowd.

Sabalenka had admitted on the eve of the tournament that she could accept if Kostyuk had feelings of "hate" towards her.

"I never said that I hate Aryna Sabalenka or any of the players. I just don't respect her because of her position in this situation," added Kostyuk, who wants Russian and Belarusian players to individually denounce the war which has raged on since February last year.