The top seed at the Heineken Open tennis tournament has battled into today's quarter finals in Auckland.
Spain's David Ferrer needed three sets to see off the second round challenge of Taiwan's Lu Yen-Hsun before winning, 6-4 2-6 6-3 in just under two hours.
Ferrer will face unseeded Slovakian Lukas Lacko in the quarter-finals, who beat Brazil's Thomaz Bellucci.
Third seed Tommy Haas defeated Dutch qualifier Igor Sijsling in straight sets 6-3 6-4 to set up a quarter-final for the German against Frenchman Gael Monfils, who ended Australian qualifier Greg Jones' run, also in straight sets.
German second seed Philipp Kohlschreiber needed three sets to see off Colombia's Alejandro Falla - Kohlschreiber now plays Belgian journeyman Xavier Malisse, who eliminated another Colombian, Santiago Giraldo.
First to reach the quarters was big-serving fourth seed Sam Querrey, the American powering past last year's losing finalist Olivier Rochus of Belgium.
Also through in straight sets is the tournament surprise package, the Canadian qualifier Jesse Levine, Levine ending American Brian Baker's run.
