Australian Open semifinalist Dayana Yastremska has released a new single, "Hearts," a collaboration with Czech singer Rodan and Latvian rapper Loopout dedicated to her native Ukraine.

Under the name D.Y., Yastremska had released a handful of singles to streaming platforms in 2020 and 2021. During her historic run to the Australian Open semifinals as a qualifier a month ago, the 23-year-old -- who celebrated each of her wins by making a heart shape with her hands -- teased an imminent revival of her pop side career.

"I like singing, but I will say it's a little bit past," Yastremska said after her quarterfinal defeat of Linda Noskova. "But in February I hope that one new song will come out. It's not just mine. It's gonna be three of us, three different countries, that we got together and we made a nice song."

Set against the backdrop of the war in Ukraine, "Hearts" is a stylistic departure from the uptempo dance-pop of Yastremska's previous work, such as "Favorite Track." Above moody synths, she describes the sound of bombs exploding across a city before encouraging listeners to "burn all fears."

Yastremska, who co-wrote the song with Loopout, said on social media:

"This is another reminder to all the people about my country, about children, and that we need support. I know people are forgetting about and getting tired of the war, but we need to be brave and stick together. This song is about strength and maturity."

The World No.26 next takes the court in in San Diego next week.