American Isner shocks Federer in Davis Cup World number three Roger Federer slumped to a shock 4-6, 6-3, 7-6 (7/4), 6-2 defeat to John Isner on Friday as the United States opened up a 2-0 Davis Cup World Group lead. Federer, playing a first round tie for the first time in eight years, saw his 15-match winning streak in the competition ended by the giant Isner on the indoor clay courts at Fribourg. Isner secured victory with three return winners as the 32-time Davis Cup champions America moved closer to a quarter-final spot. "The way I played today is the way I need to play in all my matches," said Isner, who paid tribute to captain Jim Courier. I owe it to Jim Courier -- he was on at me to hit all my shots. It's the win of my life. Courier, bidding to lead the United States to a first Davis Cup title since 2007, said Isner got his tactics just right. "The mission was to go out there and not allow an artist a canvas to work with," he said. Earlier, Mardy Fish had defeated Stanislas Wawrinka 6-2, 4-6, 4-6, 6-1, 9-7 in the opening rubber. The winners of the tie will face either France or Canada in April for a place in the semi-finals.