Cincinnati, OH, USA, 18 August 2015 | tennis.com.au

Sam Stosur has fallen to qualifier Timea Babos in a dramatic match at the Western & Southern Open in Cincinnati.

Stosur fell 7-6(6) 4-6 7-5 in two hours and 20 minutes in a match delayed by frequent rain.

The Australian lead by a break in the final set but could not finish the job as the Hungarian – who had come into the match in good form with two qualifying victories under her belt – came storming back.

Babos finished the match with a sparkling 11 aces to just one double fault to set up a second-round encounter with No.8 seed Karolina Pliskova.

After reaching the semifinals in Washington DC, Stosur has now lost her last three matches on North American hard courts.

She will be searching for form ahead of the US Open, beginning Monday 31 August.