The top four seeds advanced to the third round of the Western Southern Open in Mason, Ohio, on Wednesday, with the top three moving on in straight sets. No. 1 Daniil Medvedev of Russia rolled past U.S. wild-card entrant Mackenzie McDonald 6-2, 6-2. No. 2 Stefanos Tsitsipas of Greece downed the United States' Sebastian Korda 7-6 (5), 6-3, and No. 3 Alexander Zverev of Germany handled South Africa's Lloyd Harris 7-6 (3),