Top seeded Tommy Robredo of Spain started his campaign at the Heineken Open with a 7-6 (1) 7-6 (2) win over Simon Greul of Germany on Wednesday.

"I'm happy for the win," Robredo said.  "I don't think I played my best tennis today, but I did a good job in coming back on both sets.  In the tie-break I think I was more consistent than him and that was the key to win."

Another Spaniard and former World No 1 Juan Carlos Ferrero withdrew midway in his match against Swiss qualifier Michael Lammer at 3-1 due to a leg injury. 

Lammer will next confront eight seeded Spaniard Albert Montanes for a place in the semifinals. Montanes registered a 7-6(6) 6-2 win over local wild card Jose Statham.

"I'm very happy to reach my first ATP [World Tour] quarterfinal," Lammer said.  "I didn't expect to win this way. I'm sad for Juan Carlos; it's tough to twist your ankle in the first match of the year."

Fifth seeded and 2007 winner Philipp Kohlschreiber of Germany stayed on the course of another title with a 6-4 6-1 victory over Thomaz Bellucci of Brazil.

"I played much better today," Kohlschreiber said.  "I really like to play in Auckland - I have good memories from this tournament.  The conditions were tough, with a lot of wind, but I've played here many times and I know how to adjust."

He will next play France's Marc Gicquel, who registered a 6-0 6-3 victory over fourth seeded Nicolas Almagro.

In other matches of the day, American John Isner battled past seventh seed Juan Monaco and sixth seeded Jurgen Melzer of Austria prevailed  6-2 6-7(5) 7-6(1) against French wildcard Sebastien Grosjean.