American Amanda Anisimova, who has Russian parents, is donating part of her prize money from winning the Tie Break Tens exhibition at Indian Wells to help relief efforts in Ukraine.
The 20-year-old won $150,000 (£114,000) by beating Greece's Maria Sakkari 10-7 in the final on Tuesday.
In her winner's speech she said "every day is extremely sad" since Russia invaded Ukraine nearly two weeks ago.
"We are here and enjoying but it's very hard to just live normally," she added.
"I'll definitely be donating some of my prize money to the Ukrainian relief fund."
Highlights of the Eisenhower Cup Tie Break Tens event - where players compete in 10-point tie-breaks - will be shown on BBC Three on Wednesday, 9 March at 20:00 GMT.
Anisimova, whose mother and late father moved from Russia to the United States before she was born, follows other tennis players including Andy Murray in pledging to help Ukrainians.
More than two million people have fled Ukraine since Russia invaded its neighbour, while others remain trapped in besieged cities.
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