Geopolitical tensions simmered at the U.S. Open on Thursday as Ukrainian Marta Kostyuk refused the customary handshake at the net after losing to Belarusian Victoria Azarenka 6-2, 6-3 in the second round.

The pair exchanged a quick racket tap after Kostyuk hit the ball into the net on the third match point to send Azarenka, a three-time finalist, into the third round.

¡°Well, I wasn¡¯t surprised,¡± Azarenka said. ¡°I don¡¯t believe that making a big deal out of it is important. I always shake hands with my opponents,¡± she continued, adding that Ukrainian Dayana Yastremska had done the same after a match in Washington last month.