NEW YORK: Belgium’s Elise Mertens put American wildcard Kristie Ahn’s U.S. Open run to an abrupt end on Monday, defeating her soundly 6-1 6-1 to reach the quarter-finals. Ahn may not have gotten as much attention as fellow Americans Coco Gauff or Taylor Townsend at Flushing Meadows but she walked into Louis Armstrong Stadium with major momentum.The 27-year-old former Stanford University player had beaten Mertens in San Jose a little over month ago and reached the fourth round without dropping a set, becoming the first Asian American woman to make the round of 16 since 2000. But Mertens, seeded 25th, was too consistent, keeping her unforced error count low and winning 79% of points on first serve. Mertens will face the winner of the late match between American Taylor Townsend and Canada’s Bianca Andreescu. Ahn’s $280,000 cheque for reaching the round of 16 is nearly double her $143,000 (116,478 pounds) in prizemoney earned earlier this year. The 141st-ranked Ahn will also break into the top 100, making her eligible for more WTA events.