By Frank Pingue
TORONTO, Aug 6 (Reuters) - World number one Ash Barty fell at the first hurdle in a U.S. Open tune-up at the Rogers Cup on Tuesday but the Australian was not about to let the shock defeat rattle her confidence ahead of the season's final Grand Slam.
Top seed Barty, who had a bye into the second round, was rusty and unable to adapt quickly enough to the hard court, a surface she has not competed on since April, during her 6-7(5) 6-3 6-4 loss to American Sofia Kenin.
"At times I was missing by big margins, which is not something that I'm very used to or comfortable with," Barty told reporters.
"But it's not panic stations. It's my first match on hard court in a long time."
Despite the loss, Barty said she was able to take comfort from the fighting spirit she showed throughout the match.
World number 29 Kenin failed to serve out the opening set at 5-4 and, after losing the tiebreak, raced out to a 4-0 lead in the second only for Barty to storm back by winning three straight games to get back on serve.
Kenin broke twice early in the decider to build a 4-1 lead only for French Open champion Barty to again threaten, but the Australian ran out of tricks on the fourth match point.
"I have no idea how I was able to get out of that first set and probably should have been bageled in the second and done pretty quickly in the third, as well," said Barty.
"So I think, all in all, I was able to find a way to hang in there and make it tricky, but the polish wasn't there and Sofia was the better player in big moments today."
Barty played with tape on her right shoulder, which she said was preventative after the added stress of hitting balls that bounced higher off the court over the last couple days.
The loss left Barty's world number one ranking hanging by a thread.
She will vacate the top spot if reigning U.S. Open and Australian Open champion Naomi Osaka wins her second-round match on Wednesday or if Czech Karolina Pliskova reaches the semi-finals in Toronto.
But Barty, while disappointed at her early exit, said she was not worried about whether she retained her lofty ranking after this week, especially given it is now out of her control.
"It's just a number next to your name. It doesn't define you as a person or a player," said Barty. "If next week I'm not number one, I'm certainly not going to lose any sleep over it." (Reporting by Frank Pingue in Toronto, editing by Nick Mulvenney)