MUNICH -- Marin Cilic of Croatia advanced to the quarterfinals of the BMW Open on Thursday by defeating Horacio Zeballos of Argentina 6-3, 7-6 (7).
Cilic had eight aces and lost only seven points on his first serve while breaking Zeballos's serve three times. The third-seeded Cilic is the highest seeded player left in the last eight. The runner-up last year, he has reached the quarterfinals in Munich for the fourth time.
Seventh-seeded Nikolay Davydenko of Russia rallied to defeat German qualifier Julian Reister 3-6, 7-6 (5), 6-1. Davydenko won the tournament in 2004.
Former champion Philipp Kohlschreiber defeated "lucky loser" Denis Gremelmayr 6-3, 6-3.
Kohlschreiber will face Radek Stepanek, who outlasted German wild card Dustin Brown 7-6 (6), 6-7 (5), 6-3 despite squandering a 5-2 lead in the second set.
Fifth-seeded Florian Mayer of Germany edged Teymuraz Gabashvili of Russia 6-4, 7-6 (1) to set up a quarterfinal showdown with Bulgarian teen Grigor Dimitrov, who advanced on Wednesday.