Gilles Simon of France defeated Rui Machado of Portugal 6-3, 7-5, and No. 5 Juan Monaco of Argentina advanced when Filippo Volandri of Italy retired in the second set with an injury. Monaco was leading 6-1, 3-1.
Top-seeded David Ferrer of Spain had no trouble beating Argentine Andres Molteni 6-1, 6-0.
"I'm happy to get out of the first round, and I think he (Molteni) was a little nervous," Ferrer said.
Molteni had plenty of support from local fans, who were hoping for some revenge for Spain's victory over Argentina last year in the Davis Cup final at Seville, Spain.
"I like fans supporting the local players," Ferrer said. "It's the normal thing to do, and personally I like it."