The Argentine notched up his third Top 8 victory in a row by brushing Kevin Anderson aside 6-4 6-4 in 1 hour and 40 minutes.
It’s the 21st time del Potro has captured silverware, and his preparations for the first Masters event of the year in Indian Wells next week could hardly have gone better.
“It's a very special tournament to me,” said the champion. “I beat three Top 10 guys in the same tournament, which is very important for myself. I'm so glad to win my 21st title playing in Acapulco.”
Anderson was attempting to win the biggest title of his career, but he struggled to make an impact on his opponent’s serve. He also took a nasty tumble in the early stages of the second set after being caught flat-footed by a delightful del Potro lob.
“It was a little bit uncomfortable at first,” said Anderson, when asked about his fall. “I think in the bigger picture of things it didn't really affect things too much.
“I think he [del Potro] played really well. He's obviously a tough competitor and a great player. I just needed to do a little bit more today.”
Del Potro will overtake Anderson and become the new world No.8 when the ATP rankings are updated on Monday.