World number 66 Denis Istomin has progressed to the third round of the Atlanta Open with a straight-sets victory over Lu Yen-Hsun.
Istomin came through 7-5 6-2 to book his place in the quarter-finals.
After a close opening to the match, in which the player from Chinese Taipei had several chances to break his opponent, Istomin was able to break at 5-5, before serving out the set.
In the second set, his challenger offered little resistance as Istomin overpowered him 6-2.
He advances to the third round where he will play either Matthew Ebden or second seed Kevin Anderson.
