Yaroslava Shvedova is through to the second round of the Cincinnati Open thanks to a hard-fought win over Garbine Muguruza.

The Wimbledon runner-up slumped to her second straight first-round defeat in a 6-4 7-6[0] loss during a rain-affected match.

Qualifier Shvedova earned a crucial break of serve midway through the opening set and went on to win it, before Muguruza challenged her harder in the second.

However, the Spaniard failed to convert any of her chances and was overcome easily in the tie-break without scoring a point.

Muguruza has not won a set in competitive tennis since the Wimbledon semi-finals.