Unseeded American Sam Querrey stunned second-seeded Rafael Nadal 6-3, 7-6 (7/3) on Saturday to win the ATP Mexico Open and end the Spaniard's run of perfection in Acapulco.

Querrey, ranked 40th in the world, fired 19 aces en route to his first career victory over Nadal in five meetings. The Spaniard, winner in Acapulco in 2005 and 2013, had never even lost a set in Acapulco.

Querrey captured his ninth ATP title in an impressive week that saw him beat four top-10 players -- Belgian David Goffin, Austrian Dominic Thiem, Australian Nick Kyrgios and sixth-ranked Nadal.

Nadal, playing his first tournament since falling to Roger Federer in five sets in the Australian Open final, was denied his first hard court title since Doha in 2014.