American Jennifer Brady reached her first Grand Slam quarter-final by disposing of 2016 champion Angelique Kerber at the US Open.
German 32-year-old Kerber, a three-time major champion, lost the first set in just 22 minutes and won only 35% points on her second serve throughout.
Brady will face Croatian eighth seed Petra Martic or Yulia Putintseva next.
"It feels great, I'm so happy. I played a spectacular first set," said Brady, who received treatment on a leg injury in the second set.
Although Kerber became more competitive, the American held her nerve and sealed victory when the 17th seed sent a return long.