Top seeded and reigning champion Juan Martin del Potro defeated seventh seeded Albert Montanes 6-2, 6-2 for a place in the Estoril Open semi-finals.

"I think I played better than yesterday and my confidence is growing," said del Potro. "It is important for this tournament and the next tournaments I play. I think I am playing better than I did in the last Davis Cup tie. The Estoril crowd support me and that helps."

Del Potro will next meet third seeded Stanislas Wawrinka, who dispatched sixth seed Robin Haase of the Netherlands with a 6-1, 6-4 scoreline.

Also, France's Richard Gasquet defeated Spaniard qualifier Daniel Munoz-De La Nava 7-6(1), 6-2 and will next face fourth seeded Albert Ramos.