Fifth-seeded Spaniard David Ferrer exited the Indian Wells Masters on Tuesday after losing his third-round match to Denis Istomin 6-4, 6-3 at the Indian Wells Tennis Garden. Ferrer, who had won three titles already this year, suffered just his second loss of 2012 to go with 19 victories. He won tournaments in Auckland, Buenos Aires and Acapulco. Istomin broke Ferrer in the opening game then won the final five games of the match, breaking Ferrer three times in the second set. Istomin, who is ranked 51st in the world, fired five aces and won 80 percent of his first-serve points. Ferrer finished with five aces, three double faults, and won just four of 15 points on his second serve in the 74-minute match. Istomin advances to the fourth round, where he will play Argentina\'s Juan Martin del Potro, who beat Fernando Verdasco 6-2, 7-6 (8/6) on Tuesday. Istomin reached the final of the San Jose tournament last month, losing to Canadian Milos Raonic. Del Potro is also off to a roaring start this year, having made the quarter-finals or better at every tournament he has played. Del Potro survived two set points in the 10th game of the second set against Verdasco before closing it out in the tie-break. Del Potro hit four aces, won 71 percent of his first serve points and saved all six of his break point chances. Thomaz Bellucci of Brazil advanced in a walkover when Russian Nikolay Davydenko pulled out with a virus. American Jamie Hampton had to retire from her fourth-round match with a cramping problem, allowing fifth seed Agnieszka Radwanska to become the first player through to the quarter-finals.