Fourth seed Elina Svitolina became the highest-profile casualty in the women’s draw at the French Open after a surprise straight-sets defeat.

The Ukrainian lost 6-3 7-5 to Romania’s Mihaela Buzarnescu, the world number 33 who had never won a Grand Slam match before this week.

But Australian Open champion Caroline Wozniacki eased into the last 16.

Wozniacki, the second seed at Roland Garros, defeated France’s Pauline Parmentier 6-0 6-3.

She will next face Russian 14th seed Darya Kasatkina, who beat Greece’s Maria Sakkari 6-1 1-6 6-3.

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“Today, really, I was off and couldn’t find my rhythm, my game. I was really struggling,” said Svitolina.

“On the other hand, she was playing great tennis. She was really, really on the ball.”

Play was later cancelled for the day following a heavy spell of rain with eighth seed Petra Kvitova and 10th seed Sloane Stephens yet to start their matches.