Vondrousova looked uncomfortable throughout the contest, committing 44 unforced errors, but held her nerve to grind out a win despite dropping the first set.

Bouzkova started well, winning four straight games en route to a 5-1 lead in the opening set as several of Vondrousova’s errant shots found the net.

The 32nd seed stumbled while serving for the set, allowing Vondrousova to reclaim a break, but she broke back immediately to seal the opener.

Vondrousova launched her comeback in the second set as she produced some deft drop shots to claim two breaks and force a decider.

With her confidence restored, she made no mistake as she moved 4-3 ahead and then wrapped up victory with another break.

Vondrousova will meet the winner of the tie between fourth seed Jessica Pegula and Ukraine’s Lesia Tsurenko for a place in the semifinals.