World number one and French Open champion Ash Barty was knocked out of Wimbledon on Monday after losing 3-6 6-2 6-3 in a ferocious battle with 55th-ranked American Alison Riske.

Barty, who had been on a sensational 15-match winning run, was brought down to earth with a thud by Riske, who reached her first ever Grand Slam quarter-final at the 30th attempt and at the age of 29.

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Barty began well, serving four straight aces in the opening game on her way to winning a 21st successive set over the last three tournaments.

Yet Riske, who had spent more than four hours longer on court than Barty in the first week, dug-in for a trench battle, out-slugging the Australian to take the next two sets and set up a potential last eight clash with seven times champion Serena Williams.