Ukraine's Elina Svitolina says it is her mission "to unite the tennis community" behind her country after beating Russian Anastasia Potapova in the Monterrey Open first round.
Svitolina, wearing the blue and yellow of Ukraine's flag, won 6-2 6-1.
The 27-year-old initially refused to play the match until the WTA and ATP said Russian and Belarusian players must compete as neutral athletes.
"I was on a mission for my country," said the world number 15.
"I'm in a very sad mood, but I'm happy I'm here playing tennis.
"I think it's my mission to unite our tennis community to stand with Ukraine, to help Ukraine because what we're going through is a horrible thing for all Ukrainians.