Iga Swiatek blamed herself for a mid-match drop in form which made her first match since winning Olympic bronze a major test at the Cincinnati Masters.
The world No. 1 emerged a 6-0, 6-7 (8), 6-2 winner over qualifier Varvara Gracheva to reach the third round in her opening match at the final big event before the US Open.
Swiatek raced away with the first seven games but could not close out a 5-2 lead in the second set.
Her French opponent took full advantage, saving five match points over two games of the second set and taking the contest into a deciding third on her own fifth set point.
But five-time grand Slam winner Swiatek recovered to finally squeeze out the victory after more than two hours.
“It was not easy to finish in the second set,” the Polish winner said.. “She started playing with freedom, with nothing to lose.
“I backed down a bit and she used her chances. I’m happy I got more proactive in the third set and played more intense.
“I knew I had the game to win it – I did have five match points.
