Kei Nishikori breezed through at the ATP Abierto Mexicano Telcel as Donald Young also advanced on Monday.
Japanese second seed Nishikori, last year's runner-up at the ATP 500 event played on hard-courts, crushed qualifier Thiemo de Bakker 6-0 6-3 in the first round.
In his first tournament since winning the Memphis Open, Nishikori broke serve six times to win in an hour in Acapulco.
While Nishikori was the only seed in action, Young also progressed with a 6-3 6-3 victory over fellow left-hander Gilles Muller.
Muller sent down 10 aces but was unable to break, with Young taking his chances to progress.
Mexicans Luis Patino, Tigre Hank and Lucas Gomez failed to capitalise on their wildcards.
Hank was thrashed 6-1 6-2 by Frenchman Adrian Mannarino, while Patino went down to Robin Haase by the same scoreline.
Gomez put up more of a fight but was downed by Victor Estrella Burgos 6-4 6-2.
Ukrainian Illya Marchenko booked his spot in the second round with a 6-2 7-6 (7-4) victory over American teenager Tommy Paul.