MEMPHIS, Tenn. (AP) Nikoloz Basilashvili beat top-seeded Ivo Karlovic 7-6 (2), 6-3 on Thursday to advance to the Memphis Open quarterfinals.
Basilashvili, ranked 67th in the world, never lost his serve and allowed the 20th-ranked Karlovic just one break-point opportunity.
Basilashvili will face the winner of the match between Matthew Ebden and Taylor Fritz.
In other second-round action, fourth-seeded Steve Johnson beat fellow American Tim Smyczek 3-6, 6-4, 6-2. Johnson lost the first set and fell behind 3-1 in the second set before rallying.
Johnson will face Mikhail Kukushkin, a 6-3, 6-0 winner over Darian King.
Karlovic's loss leaves Johnson and No. 2 Isner as the only seeds left.