John Isner looking forward to "fun" Roger Federer quarter-final

John Isner has claimed that his Olympic quarter-final with world number Roger Federer will be a "very fun match".

The American seventh seed defeated Janko Tipsarevic in straight sets in the last round, while Federer also came through in two against Denis Istomin.

"I'm going to go for it," Isner told reporters. "Not be too crazy, but I'm going to have to try to dictate play. If he's on the offence, I don't really stand a chance.

"It's going to be a very fun match, I'm looking forward to it."

Kei Nishikori or Juan Martin del Potro awaits the winner of Isner's encounter with Federer in the semi-finals.