Third seed Guillermo Coria eased his way into round three of the Nasdaq-100 Open with a 7-6 6-0 victory over South African Wayne Ferreira.
But 10th seed Nicolas Massu and 16th seed Mardy Fish both bowed out, Massu losing 7-6 6-1 to Andre Pavel and Fish going down 6-4 6-4 to Julien Benneteau.
Pavel will now play Lleyton Hewitt, who beat Sweden's Robin Soderling 6-4 6-2.
But top seed Roger Federer's opening match against Nikolay Davydenko was postponed because of torrential rain.
Before the downpour, American veteran Todd Martin reached the third round with a 6-3 5-7 7-5 defeat of 29th seed Jarkko Nieminen.
But Goran Ivanisevic saw his injury problems continue when he withdrew from him second-round match against 32nd seed Rafael Nadal with shoulder pain.