The American John Isner has toppled the top seed Tommy Robredo of Spain to advance to the semi finals of the Heineken Open in Auckland.
Isner won the match 7-6 3-6 6-4.
Spain's Albert Montanes will play Isner in the semi finals.
Montanes had a straight sets win over Michael Lammer of Switzerland.
Arnaud Clement of France won the third quarter final of the day, beating Jurgen Meltzen of Austria, 6-2, 7-5.
Clement will play either Philipp Kohlscreiber or Marc Giquel in the semis.
