Querrey captured his ninth ATP title after an impressive week in Acapulco during which he beat two other top 10 players – David Goffin and Dominic Thiem as well as Nick Kyrgios who eliminated the top seed and world number two Novak Djokovic. Ranked 40th at the start of the tournament, Querrey is projected to rise to 26, his highest standing since August 2013.
"It's definitely a tournament that I'm going to remember for the rest of my life," said Querrey. "It's just one of those weeks where I got in the zone and everything was working for me. I hope I can have more like this."
He added: "After the match against Goffin, I knew I could go far here if I continued to play at that level," he added. "My forehand and backhand were great and my serve bailed me out of trouble when I needed it."
Querrey fired 19 aces past 30-year-old Nadal during the 94 minute final. He backed up his serves with powerful, precise groundstrokes to become the first American to hoist the Mexico Open trophy since its inception 24 years ago.
Nadal, the 2005 and 2013 champion, had never lost a set in Acapulco.
"Sam played very well, almost reaching perfection," Nadal said. "I played under a lot of pressure because of his serve and baseline game. He left me with very few options, and the few I had he also played good."