Fourth-seeded Lu Yen-Hsun of Taiwan rallied for a three-set victory over US qualifier Denis Kudla on Thursday to reach the quarter-finals of the US National Indoor Tennis Championships.
Lu, 30, downed Kudla 3-6, 6-3, 6-3 to set up a clash with another American qualifier, Alex Kuznetsov, in the $647,000 ATP event.
Kuznetsov toppled eighth-seeded Mikhail Kukushkin of Kazakhstan 2-6, 6-3, 7-6 (7/1).
Lu will be hoping to improve on his career-best season start. He is 8-2 in 2014 and reached his first ATP Tour final last month in Auckland.
Second-seeded Spaniard Feliciano Lopez and third-seeded Australian Lleyton Hewitt were to open their Memphis campaigns later Thursday with second-round matches.
Lopez, who fell to Japan's Kei Nishikori in last year's final here, faced Croatian Ivo Karlovic while Hewitt was up against Marcos Baghdatis of Cyprus.
Nishikori, ranked 17th in the world and a top seed for the first time at an ATP event, booked his quarter-final berth on Wednesday with a 6-4, 6-4 victory over Germany's Benjamin Becker.