Ukraine’s Lesia Tsurenko stunned defending champion Garbine Muguruza to claim victory in the second round of the Western & Southern Open in Cincinnati.

Tsurenko fought from a set down and a loss of serve in the final set to defeat the number seven seed, who was back on court for the first time since Wimbledon last month.

After withdrawing from San Jose and Montreal due to an arm injury, Muguruza got off to a nervy start, saving two break points in the opening game and failing to convert her own chances in the second.

But Tsurenko had too many unforced errors – 15 in the first set – and lost her serve twice to lose the opening set 6-2.

It was in the second and third where she really found her momentum and despite both players struggling with double faults, the world number 44 prevailed to take the next two sets 6-4, 6-4.

Number three seed Sloane Stephens also advanced through the second round, beating qualifier Tatjana Maria in straight sets 6-3 6-2.

She will now face 15th seed Elise Mertens, who beat Sweden’s Rebecca Peterson 3-6 6-2 7-6 (7/1), while Kiki Bertens progressed after second seed Caroline Wozniacki retired, and Angelique Kerber defeated Anastasia Pavlyuchenkova 4-6 7-5 6-4.

Other second-round winners included 16th seed Ashleigh Barty and American Madison Keys. Number one seed Simona Halep’s match against Ajla Tomljanovic was suspended due to rain and will be completed on Thursday.