HOUSTON (AFP) - Ryan Sweeting fended off six break points in the final game Wednesday and upset second-seeded Sam Querrey 3-6, 7-6 (7/5), 6-3 in the second round of the ATP's US Men's Clay Court Championships. Sweeting survived 18 of 24 break points he faced against his fellow American to book his place in the quarter-finals. Querrey, meanwhile, lost three points on his usually booming serve in the second-set tiebreaker, including a double-fault for set point. In a match that featured 11 total service breaks, the two traded breaks in one span of seven straight games -- including the last five games of the second set through the first two games of the third. "Overall I was happy with the way I played," Sweeting said. "I started off really slow and he broke me in the first game and served really well. I was standing way back on his serves and had no chance to break him.