VIENNA (AFP) - Fernando Gonzalez fought off five match points before defeating Latvia's Ernests Gulbis 4-6, 7-6 (13/11), 6-1 to reach the quarter-finals of the Austrian Open on Wednesday. The number two seed from Chile, who the day before had needed 138 minutes to dispose of Simone Bolelli, was on court for a further 130 minutes before securing his victory. Gulbis, a French Open quarter-finalist, stretched the more experienced Gonzalez all the way in the opening two sets with his more varied game keeping his opponent guessing. Mixing penetrating groundstrokes, frequent use of the dropshot and often playing serve and volley, he immediately recovered a break to level the first set at 3-3 and then broke against for the set with a perfectly executed drop volley. Both players had break point opportunities in the second set, before Gulbis netted a weak backhand to give Gonzalez a break for 5-4. But the Chilean failed to serve out the set, and then was also unable to convert any of three break points at 5-5 as the set moved to a dramatic conclusion. Gulbis held five match points in the 24-point tiebreak, before a double-fault allowed Gonzalez to level the match on his third set point. Gonzalez quickly established a lead in the deciding set, giving up just four points in the first three games before a final break, to love, left him serving for victory. "There were many match points and he was in control of the match," said Gonzalez. "Most of the time I was the guy who was running and trying to reach some balls, and he was the one who was going for it every time. "But I'm happy the way that I turned back the match and in the end I won 6-1 and that's really good for my confidence. Maybe I'm not playing my best tennis and not feeling my forehand like I used to, but anyway I'm fighting and I'm still winning." Third seed Juan Martin Del Potro from Argentina, playing his first match as a member of the world's top 10, withstood a spirited challenge from 219th-ranked wild card Martin Fischer, beating the Austrian 7-6 (9/7), 7-6 (7/5) to reach the second round. Del Potro saved a set point in the first set tiebreak before claiming it on his own third set point. Fischer also had an opportunity to claim the second set, breaking to lead 5-4 but then dropping his serve to love. Fischer continued to challenge and served at 5-4 in tiebreak before Del Potro sealed victory on his third match point. Germany's Philipp Petzschner followed up his victory over top seed Stanislas Wawrinka by beating Czech qualifier Jan Hernych 6-3, 6-4, and fifth seeded Spaniard Fernando Verdasco overwhelmed Argentina's Guillermo Canas 6-1, 6-2. Eighth seeded Gael Monfils of France recovered from a sluggish start in which he dropped his opening service game to defeat Austria's Alexander Peya 3-6, 6-1, 6-3 in the remaining first round match. Spain's Carlos Moya defeated Eduardo Schwank of Argentina 6-2, 6-3 in a second round tie.