Spain's Garbine Muguruza plays a forehand return to Australia's Samantha Stosur during their women's singles third round match on day seven of The Roland Garros 2018 French Open tennis tournament in Paris on Saturday. CHRISTOPHE SIMON / AFP

Spain's Garbine Muguruza, world No. 3, on Saturday qualified for the French Open round of 16 for the fifth straight year, beating veteran Australian player Samantha Stosur 6-0, 6-2.