Defending champion Marin Cilic survived a scare from Marcel Granollers before advancing to the quarter-finals of the 400,000-dollar ATP Chennai Open on Wednesday. The world number 14 fought back from a set down to beat the valiant 91st-ranked Spaniard 6-7 (3/7), 6-3, 6-4 after two hours and 46 minutes of intense tennis. It was Croatian Cilic's fourth successive win over Granollers, including a semi- final victory in the same tournament last year. The second-seeded Cilic is favoured to retain the title after top seed Robin Soderling of Sweden was knocked out by American Robby Ginepri in the first round on Tuesday. Both players held their serve in the first set to force the tie-breaker, which Granollers won after Cilic appeared to lose his composure following two disputed line calls. Granollers and Cilic traded two breaks each in the second set, before the Croat broke again in the eighth game and easily held his own serve in the ninth to draw level. Cilic went a break up in the seventh game of the third set, ending Granollers' resistance on the show court of the Nungambakkam Tennis Stadium. 'It was not easy for me today,' said Cilic. 'Marcel played a very good game, but once I broke him in the second set, my game started to improve and I served and volleyed much better.' Cilic conceded that a few line calls during crucial moments of the match upset him. 'Some calls were suspicious,' he said. 'They hurt me more than they hurt him. It often happened on crucial points. But that's tennis. You just have to get on with the game.' Cilic's quarter-final opponent will be 107th-ranked Santiago Giraldo of Colombia, who beat Czeck Jan Hajek 6-4, 6-2 in 66 minutes. Fourth seed Janko Tipsarevic of Serbia cruised into the last eight with an emphatic 6-2, 6-1 win over India's top player, Somdev Devvarman, in just 78 minutes. Devvarman, a surprise finalist here last year after being given a wildcard, held his serve just once in the match against his fancied opponent, ranked 88 places above him at 38. Tipsarevic next plays Thiemo de Bakker of the Netherlands, who advanced to the quarter-finals with a 6-3, 6-4 demolition of compatriot Robin Hasse. 