The contest looked like it was going to be a tight affair as it featured three service breaks at the start but Del Potro - a former world number four who is currently ranked 46th after missing most of last year with a wrist injury - took control and closed the set with an ace.
"Everything was perfect. I am playing better day by day, tournament by tournament and feel ready to win all of them," Del Potro said.
The Argentine used his powerful and accurate forehand in the second set to frustrate the Spaniard, who continued to make unforced errors and succumbed on the third match point by sending a shot wide.
"I served really well, was very confident with my forehand and took all my opportunities," Del Potro added.
The tall Argentine had knocked out top seed Robin Soderling in the quarter-finals and then swept past Uruguay's Pablo Cuevas, both in straight sets.
Verdasco appeared to be exhausted after he was forced to play his quarter-final and semi-final matches back-to-back on Saturday, although he only had to play one set against Milos Raonic in his last four encounter as the Canadian quit injured.
"He (Del Potro) played much better than me. I did not have many chances to put him in trouble, he was playing hard and deep," Verdasco said.