ZAGREB, Croatia — Top-seeded Ivan Ljubicic served 19 aces and beat Teimuraz Gabashvili of Russia 6-2, 6-7 (5), 6-3 to advance to the semifinals at the Zagreb Indoors today.

Ljubicic, the 2006 champion and 2007 finalist, improved to 12-1 in Zagreb. The Croat is the last seeded player left after No. 8 Janko Tipsarevic of Serbia lost 3-6, 6-4, 6-2 to Sergiy Stakhovsky of Ukraine.

Ljubicic will play either Robin Haase of the Netherlands or Mario Ancic of Croatia.

Stakhovsky is the first lucky loser to reach an ATP semifinal match since Ivan Navarro in Valencia, Spain, in April 2007. He joined the event after Michael Llodra, last week's Rotterdam winner, withdrew.

Stakhovsky will play either Simone Bolelli of Italy or Olivier Rochus of Belgium in the semifinals.