TORONTO (REUTERS) - World number one Ash Barty's US Open tune-up got off to a rocky start as the Australian suffered a shock 6-7(5) 6-3 6-4 loss to American Sofia Kenin in the second round on Tuesday (Aug 6) at the Rogers Cup.
Barty, playing for the first time since falling in the last 16 at Wimbledon, struggled in the second set as she dropped the opening four games and Kenin took advantage en route to her first victory in four meetings with the Australian.
Kenin nearly squandered a 4-1 cushion in the decider but held her nerve and closed out the match when a misfiring Barty sent a routine forehand long.
"I am just really tired to be honest," Kenin said in her on-court interview. "Such a tough player and it was a tough match and I am just so happy to have pulled through."
Next up for Kenin will be either former world number one Victoria Azarenka, who earlier beat hard-hitting Italian Camila Giorgi 6-2 6-2, or Ukraine's Dayana Yastremska.
Kenin got an early break in the match to go ahead 2-1 but Barty broke back in the 10th game to level the opening set before taking control in what was mostly a lopsided tiebreak.
But Barty dropped her first two service games of the second set and was quickly staring at a 4-0 deficit that she nearly erased until Kenin stood firm to force a decider where she charged out to 4-1 lead and held off any comeback plans by her opponent.
In earlier action, seven-times Grand Slam champion Venus Williams was eliminated in the first round after suffering a 6-4 6-2 loss to Spaniard Carla Suarez-Navarro, who will next face Estonian 16th seed Annett Kontaveit.
Williams, who has now lost four consecutive matches, was ultimately undone by a slew of unforced errors and double faults that allowed Suarez-Navarro to reel off the final four games of the match to advance.
"She was just extra sharp," said Williams.
"And I played a lot of great points but just didn't put enough in a row."
In other first round action, Wimbledon quarter-finalist Zhang Shuai was a 7-6(5) 6-2 winner over Latvia's Anastasija Sevastova and will next face Russian qualifier Ekaterina Alexandrova, who beat Japan's Misaki Doi 6-2 6-2.
Czech Katerina Siniakova, German qualifier Tatjana Maria and Polish qualifier Iga Swiatek also reached the Round of 32 in Toronto, which is part of the U.S. Open Series leading up to the year's season's final Grand Slam.
An all-Canadian first-round matchup featuring Indian Wells champion Bianca Andreescu and wildcard Eugenie Bouchard will open the evening session followed by a clash between seventh-seeded Sloane Stephens and Czech qualifier Marie Bouzkova.