Amersfoort:Two Spanish clay-court specialists, top seed Albert Costa and defending champion Alex Corretja, both progressed to the second round of the $381,000 Energis Open with wins over unseeded opponents. Costa came back from a set down to oust Oleg Ogorodov of Uzbekistan, 3-6, 6-3, 6-2 on the newly laid clay courts at the Bokkeduinen sports club, while Corretja cruised past Brazilian Alexander Simoni, 6-2, 6-4. It was Costa's first ATP tour win since his Roland Garros title. It followed last week's shock first-round loss to French qualifier Paul-Henri Mathieu in Gstaad, the tournament which Corretja won last week. Third-seeded Argentinean Gaston Gaudio downed unseeded Russian Nicolai Davydenko in a topsy-turvy three-setter - 6-1, 1-6, 6-1. But another Argentinean seed, Mariano Zabaleta (No.7) tumbled out against Amersfoort-born Dutchman John van Lottum, 7-5, 6-4. Dutchman Martin Verkerk downed Argentinean qualifier Sebastian Prieto, 6-3, 3-6, 6-3, but another home favourite Jan Siemerink was eliminated by Dane Kristian Pless - 6-2, 7-6 (7/1).