Third seed Dominic Thiem survived a huge scare to reach the Roland Garros quarter-finals for a fifth straight year on Sunday, battling to a 6-4, 6-4, 5-7, 3-6, 6-3 win over French wildcard Hugo Gaston, the world number 239. US Open champion Thiem, the runner-up to Rafael Nadal for the last two years in Paris, will face Argentine 12th seed Diego Schwartzman for a place in the semi-finals. Defeat for Gaston ended home hopes in the men's singles for another year but he went down fighting, having knocked out former champion Stan Wawrinka in five sets in the previous round. dj/mw