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.