Reigning champion Roger Federer and last year's runner-up Juan Martin del Potro were a pair of second-round winners Thursday at the $1.7 million ABN AMRO World Tennis Tournament.
The top-seeded former world No. 1 Federer took care of Dutch wild card Thiemo de Bakker 6-3, 6-4 in 62 minutes, while the second-seeded del Potro topped talented Latvian qualifier Ernests Gulbis 7-6 (7-5), 6-3 in 1 hour, 39 minutes on the indoor hardcourts at Ahoy Rotterdam. Gulbis smacked 12 aces in a losing effort and the formidable del Potro was not broken on Day 4.
The reigning Wimbledon champion and 17-time major titlist Federer beat del Potro in last year's marquee finale here and also titled in Rotterdam in 2005.
Federer will face capable Frenchman Julien Benneteau in Friday's quarterfinals, while del Potro will encounter Finnish veteran Jarkko Nieminen.
An upset came when former Australian Open runner-up Marcos Baghdatis knocked out fourth-seeded Richard Gasquet 6-4, 6-4. The world No. 10 Gasquet had been 15-1 this season, including a title run in Montpellier in his native France last week.
Also, the aforementioned Nieminen outlasted German qualifier Matthias Bachinger 6-3, 5-7, 6-3 and promising Slovak Martin Klizan dismissed Dutch wild card Igor Sijsling 6-2, 6-4.
Friday's other quarterfinals will pit fifth-seeded Frenchman Gilles Simon against Klizan and Bulgarian Grigor Dimitrov versus Baghdatis.