Jack Sock and Marcos Baghdatis progressed to the second round of Memphis ATP event.
America's Sock advanced with a 7-5, 1-6, 7-6 (5) victory over France's Adrian Mannarino Tuesday, reports Xinhua.
Baghdatis of Cyprus won his first match of the year by defeating US qualifier Rajeev Ram.
No.8 seed Mikhail Kukushkin and Croatian Ivo Karlovic also reached the second round.
Japan's Kei Nishikori, ranked 16th in the world, is the top seed in the tournament.
