Chela won this tournament in 2000 and 2007 and was the runner-up in 2006.
In other first-round encounters, Potito Starace defeated fellow Italian Alessandro Giannessi 6-2, 7-5, Pablo Andujar of Spain ousted Leonardo Mayer of Argentina, 7-6 (7-5), 6-3 and Frenchman Benoit Paire got the better of Juan Sebastian Cabal of Colombia, 7-6 (7-3), 7-6 (8-6).
This week's top seeds are Spanish stars David Ferrer and Nicolas Almagro. Ferrer topped Almagro in last week's title match in Buenos Aires, where Almagro was fresh off his championship in Sao Paulo the week before. Ferrer is also the two-time reigning champion here in Acapulco, where he topped Almagro in last year's all-Spanish finale. Almagro titled here back-to-back in 2008 and 2009.
The 2012 Acapulco champ will receive a check for $277,915.