Jessica Pegula's hopes of a deep run in Paris were ended in comprehensive fashion by Belgian Elise Mertens. The 28th seed cruised to a 6-1, 6-3 victory to reach the fourth round for the third time. World number three Pegula, who only has two WTA Tour titles to her name, has still never passed the quarter-final stage of a Grand Slam tournament. "I'm very happy to win in two sets. She's a very good player," said Mertens. The former Australian Open semi-finalist will next face the winner of an all-Russian tie between Anastasia Potapova and Anastasia Pavlyuchenkova.