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, backed up by powerful, precise groundstrokes, en route to his first career victory over Nadal in five meetings. The Spaniard, the 2005 and 2013 champion, had never even lost a set in Acapulco. 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.Querrey surrendered just four points on his serve in the opening set and he broke Nadal at love to seize a 5-3 advantage.He served it out comfortably, firing a forehand winner on his second set point after just half an hour.Nadal made more inroads in the second set, but couldn’t convert any of his six break chances. That included five in the eighth game — three of which Querrey neutralized with aces. They went on serve to the tiebreaker. A brace of baseline errors from Nadal gave Querrey a 6-3 lead and a chance to serve for the title, with Nadal sending a forehand long on the American’s first match point. Nadal, 30, was looking for his 70th career victory and had marched to the final in Mexico without dropping a set, but within 29 minutes he was on the backfoot with Querrey already a break ahead. Nadal responded in the second set with the support of the majority of the Acapulco crowd, but somehow failed to take any of the six break point opportunities he created for himself, five of which came in the crucial eighth game, as he ultimately lost out via a tiebreak 7-6.