Stefanos Tsitsipas and Petros Tsitsipas earned a win in more ways than one on Wednesday in Rotterdam.

The Greek brothers defeated last week’s Singapore Tennis Open champions, Sander Gille and Joran Vliegen, 6-2, 6-3 to reach the second round of the ABN AMRO World Tennis Tournament. The victory doesn’t just send them to the second round, though. It benefits children.

After winning his singles match against Egor Gerasimov on Tuesday, Stefanos said that for each tour-level doubles match he wins with his brother, he will donate 3,000 euros to Mazi gia to Paidi (Together For Children), whose mission is, “to provide immediate and effective support to children, families, and individuals with disabilities who are in need”.