Elina Svitolina was expected to challenge for French Open glory but the fourth seed was dumped out by Mihaela Buzarnescu in the third round on Friday.

After triumphing at the Internazionali d'Italia by comfortably beating Simona Halep less than two weeks ago, Svitolina looked set for a deep run at Roland Garros.

However, the Ukrainian went down 6-3 7-5 against Buzarnescu, who will face Madison Keys in the fourth round after she overcame Naomi Osaka.

Buzarnescu had never won a main draw match at a grand slam prior to this week, but she got her third in the space of five days by hitting 20 more winners than Svitolina.

The world number four was far below her best, committing 29 unforced errors and only managing to win 46 per cent of points on her first serve.

Svitolina missed a chance to force a decider after breaking for a 5-4 lead in the second set, and Buzarnescu – ranked 377th in the world just a year ago – turned the match around to claim the biggest upset of the tournament.