AP, Paris :Roger Federer finally cracked under the unrelenting serve of John Inser, losing 7-6 (3), 3-6, 7-6 (5) to the 13th-seeded American in the third round of the Paris Masters on Thursday.The 17-time Grand Slam champion looked like he might grind out a win, saving all six break points and fighting back from 6-2 down in the decisive tiebreaker. But the Swiss star’s resistance ended when Isner – who had 27 aces – hit a looping serve to his backhand.”It’s tough going out of a tournament without losing your serve,” the third-seeded Federer said.Fourteen-time major winner Rafael Nadal, seeded seventh, almost followed him through the exit door, saving a match point in a 4-6, 7-6 (6), 6-2 win against 11th-seeded Kevin Anderson of South Africa.”Very tough match, he served amazing. I feel very lucky to be through,” Nadal said. “This type of match a couple of months ago I would not have had chances to win. In terms of mentality I (am) more calm.”Top-ranked Novak Djokovic was not at his best, either, advancing to the quarterfinals by beating 14th-seeded Gilles Simon 6-3, 7-5.But Federer’s defeat came as a genuine surprise. Having won his sixth title of the season and 88th of his career at the Swiss Indoors last Sunday, and after racing past Italian Andreas Seppi in just 47 minutes on Wednesday, he was full of confidence.Federer held a 5-1 career lead over Isner, beating him in the U.S. Open fourth round this year. “I thought he did very well today when he needed it,” Federer said.”I thought he served great.”Federer briefly needed treatment at the start of the second set because of a sore arm, but quickly recovered, insisting “it didn’t affect me in the third set and it’s not serious.”Isner called it one of the “top five” wins of his career.”He’s an incredible player, obviously. My favorite player and the greatest of all time,” Isner said. “It was a huge win for me. I’m very proud.”