Dallas (USA), Feb 10 : American star John Isner blasted 30 aces and won 89 percent of his first service points as he defeated South Africa's Kevin Anderson in three hard-fought sets at the ATP Dallas Open here. Isner, who did not face a single breakpoint, had an opportunity to win the match in straight sets but came back strongly to win the slugfest between two of the game's top servers. Isner won 7-6(1), 6-7(7), 7-6(6) to reach the quarter-finals at the Styslinger/Altec Tennis Complex here. Isner had match point on his serve in the second-set tie-break but hit a double fault. But the home favourite, who lives within walking distance of the venue and trains at this facility when he is home in Dallas, fought until the end in front of a raucous crowd. "It was a good atmosphere for sure and very happy to win that match, especially when I truthfully kind of choked in the second set. Just great to win and I knew it was going to be a coin flip match," Isner said after the match. "I told my friends, 'This is a coin flip, this is what it is.' I haven't played much, he had a match under his belt. It just was going to be tough the whole way, so hopefully, I can build on this." Next up for the third seed will be a clash with one of two qualifiers. Canadian Vasek Pospisil will face Austrian Jurij Rodionov to earn a chance at taking down the American, according to a report on the ATP Tour website Top seed Taylor Fritz also moved through, albeit in a more straightforward fashion. Fritz, who recently moved into the top 20, eliminated former top-10 star Jack Sock 6-1, 6-4 in 67 minutes. "I've never been in this position before and I have a lot of expectations of myself. Obviously, I expect to win the tournament," Fritz was quoted as saying in the report. "It's kind of cool being here knowing that I am the top seed." In other action, seventh seed Marcos Giron rallied from a set and a break down to eliminate British qualifier Liam Broady 3-6, 6-3, 6-1 after one hour and 40 minutes. Giron will play top seed Taylor Fritz in the last eight. Australian Jordan Thompson also reached the quarter-finals with a 7-5, 7-6(1) win against eighth seed Brandon Nakashima. In first-round action, fifth seed Adrian Mannarino battled through a final-set tie-break. The Frenchman clawed past American Steve Johnson 6-7(2), 6-2, 7-6(2) and will play Japanese lefty Yoshihito Nishioka. /IANS