Nadal, who last won this event in 2005, was appearing in his third final of the year. He won in Sao Paulo on February 17 and was runner-up in Vina del Mar, Chile, the previous week.
"I have had some difficult months, especially during my time away from tennis," admitted Nadal afterwards.
"But I take with me fond memories of returning to Acapulco
"I feel good being back on court. I have to thank my family and everyone involved in my rehabilitation. It has been a difficult time over the last few months."
The former world number one needed just 65 minutes to dispatch his countryman.
Nadal had won 13 of the pair's previous 14 meetings on clay and immediately showed why as he broke three times to take the first set at a canter.
He saved both break points he faced, with Ferrer winning just seven points on serve in the first set.
Ferrer improved in the second set but could make little impression on his opponent's delivery as Nadal cruised to his 38th claycourt title.
Follow us @SprtNationalUAE