(CNN) Ukrainian tennis star Elina Svitolina says she will donate all the prize money she wins at the Monterrey Open to the Ukrainian army.
The world No. 15, wearing the yellow and blue of Ukraine, defeated Russia's Anastasia Potapova -- who was not competing under the Russian flag following new sanctions from the International Tennis Federation (ITF) -- 6-2 6-1 to reach the second round in Mexico.
Svitolina had originally said she would not compete on the WTA Tour against players from Russia or Belarus competing under their respective flags following the invasion of Ukraine but reversed her decision after Tuesday's joint ruling from the ITF, WTA and ATP.
"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," she said in her on court interview. "So thank you so much for your support.
"In general, I was just focused," she added. "I was on a mission for my country."
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Svitolina, the No. 1 seed in Monterrey and its 2020 champion, will face Bulgarian qualifier Viktoriya Tomova in the second round.
"It's a very special atmosphere each time that I play here and especially today it's a very special match for me and moment," she said.
"I'm in a very sad mood, but I'm happy that I'm here playing tennis -- it's nice to play in front of you, thank you."
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In the Lyon Open, fellow Ukrainian tennis player Dayana Yastremska sank to her knees after beating Romania's Ana Bogdan 3-6 7-6 7-6 in what she called "the hardest match of my life."
The 21-year-old, who saved two match points in the three-hour epic, fled Ukraine by boat last week after spending two nights sheltering in an underground car park with her younger sister.
Yastremska traveled to Romania and then Lyon, where she had a wildcard for the tournament.
"I'm happy that I won for my country, but at the same time, I'm very sad," she said in her on court interview, the Ukrainian flag draped over her shoulders. "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 are really heroes. I hope everything is going to finish soon."