TORONTO: World number one Ashleigh Barty crashed out of the WTA tournament in Toronto on Tuesday, falling in three sets in her second-round opener to 29th-ranked American Sofia Kenin.

Australia's Barty, the French Open champion who was competing for the first time since a fourth-round exit at Wimbledon, battled back from an early break in the opening set, but she was unable to do the same in the next two sets as 20-year-old Kenin triumphed 6-7 (5/7), 6-3, 6-4.

Kenin, who has climbed the rankings this season with wins in Charleston and Mallorca and a runner-up finish in Acapulco, will face either former world number one Victoria Azarenka or Ukraine's Dayana Yastremska in the third round.

The defeat puts Barty's number one ranking in jeopardy, with both Japan's Naomi Osaka and Czech Karolina Pliskova eyeing the top spot.