Querrey, ranked 19th entering the week and a three-time winner on the tour this season, was beaten by Dustin Brown, 6-4, 6-3, in 47 minutes.

Brown had 14 aces and won points on 33 of his 34 first serves en route to his first victory against a player ranked in the top 20.

Brown, who entered the week ranked 108th after being in the 400s a year ago, relied on a quick pace and big serve to frustrate the top American in the tournament.

“Half the time I was walking over to the other side and the ball was in the air for him to serve,’’ Querrey said of Brown’s fast approach.

The 25-year-old Jamaican took control by breaking Querrey to go up, 3-2, in the fifth game of the second set, winning with a well-placed drop shot at the net.

“I wasn’t expecting to break him. I knew I was serving well,’’ Brown said. “When I broke him, I just wanted to continue to serve well. Everything just struck together for me. It’s going to take a while to sink in.’’

Both players held serve and Brown led, 4-3, at the changeover. He didn’t sit during the break, came back out and closed the eighth game with three straight aces.

Querrey seemed surprised by Brown’s different style grip and his ability to beat him with cuts and slices. The match ended when Querrey hit a forehand return into the net after Brown moved to match point with a backhand passing shot down the sideline.

Querrey won in Memphis, Belgrade and at Queen’s Club so far this season. Last year, he was the first American in five years to advance to three straight finals, including a runner-up in Newport. He won the Los Angeles Open and was runner-up at Pilot Pen.

“He’s a very unorthodox player,’’ Querrey said. “You don’t see that often. Kudos to him.’’

In other matches, No. 5 seed Mardy Fish advanced to the quaterfinals with a 6-2, 6-0 victory over Somdev Dewarman in 66 minutes. Fish needed just 51 minutes to advance on Tuesday.

“You know what to expect when you come here because they’re more soft than the courts over in London,’’ Fish said of Newport’s grass courts. “They’re sort of like first-strike tennis. I feel like that suits my style.’’