INTERNATIONAL: Dressed in Ukraine's blue and gold colors, a fired-up Elina Svitolina thrashed Russian Anastasia Potapova in Mexico on Tuesday and said it was her mission to unite the tennis world behind her country following Russia's invasion.

Svitolina had initially refused to play her opening match against Potapova at the Monterrey Open but went ahead after tennis authorities decided to ban Russian and Belarusian players from competing under the name and flag of their countries.

That decision followed Russia's invasion of Ukraine last week, which Russia calls a "special operation". Belarus has been a key staging area for the invasion.

"I'm in a very sad mood but I'm happy that I'm here, playing tennis here, so it's so nice to play in front of you, thank you."

"I was just focused from the beginning, for me it was just very important to be ready for anything that comes my way, to be all the time moving my legs and serving well, I think I served really good today, and in general I was just focused. I was on a mission for my country."

"Yes, it's a very very special event this one for me. All the prize money that I'm going to earn here is going to the Ukrainian army, so thank you so much for your support."

Svitolina, defeated Potapova 6-2 6-1, thumping her chest repeatedly on the court.

The players exchanged a few words at the net after the match before Svitolina showed her appreciation for the support from the crowd.

Television graphics had a blank space next to where Potapova's flag and the country would normally have been.

In Lyon on Tuesday, fellow Ukrainian Dayana Yastremska collapsed in a heap on the court after her victory over Romanian Ana Bogdan at the WTA 250 tournament.

The 21-year-old and her younger sister had spent two nights in an underground car park last week before their parents sent them out of Ukraine by boat to Romania and then safely to France.

"I'm happy that I won for my country, but at the same time I'm very sad," said Yastremska, who wrapped herself in a Ukrainian flag after her 3-6 7-6(7) 7-6(7) victory.

"My heart stays at home, and my mind is fighting here, so it's very difficult to find the concentration, to find the balance.

"This win, compared to what's going on in my country, is nothing. But I'm happy, at least, I'm also fighting for my country. I'm really proud of the Ukrainians and they're really heroes. I hope everything is going to finish soon."