* Nadal beats Mayer in straight sets
* Will face compatriot Almagro in last four (Adds quote, details)
By David Alire Garcia
ACAPULCO, Feb 28 (Reuters) - Former world number one Rafael Nadal breezed through to the semi-finals of the Mexican Open on Thursday, dispatching Argentine Leonardo Mayer in straight sets 6-1 7-5.
The second-seeded Nadal will face fellow Spaniard Nicolas Almagro on Friday.
It was another routine victory for the 11-time Grand Slam champion, who is in the midst of a three tournament comeback after a knee injury forced him to take a seven-month hiatus from the tour.
"I'm enjoying playing tennis again," Nadal told reporters. "When you are recuperating there are always going to be bad days, but right now there are more good days than bad."
Tournament top-seed and defending champion David Ferrer also reached the semi-finals on Thursday with a 6-3 6-1 victory over Italy's Paolo Lorenzi.
The Spaniard will next face Italian Fabio Fognini.
Earlier this month Nadal made the final of the VTR Open in Chile, and followed that up by claiming the Brazil Open title.
Since returning to competition on Feb. 5 in Santiago, Nadal has stuck to clay court events that are easier on his still-recovering left knee.
Nadal has 37 titles on clay over the course of his career, including seven French Open championships. (Reporting by David Alire Garcia. Editing by Patrick Johnston)