The first Aussie to defeat Federer since '99.

Australian tennis player John Millman, who is currently ranked 55th in the world, has just knocked Roger Federer out of the US Open.

Millman stunned the sport after beating Federer in an entertaining four sets 3-6, 7-5, 7-6, 7-6. The surprising victory has made him the first Aussie to defeat Roger Federer in a grand slam match since Pat Rafter in 1999.

"A little bit of disbelief, he’s been a hero of mine,” Millman responded post-match to a comment that he'd just beaten possibly the greatest tennis player of all-time.

“He’s definitely not at his best, but I’ll take it.”

It's the first top ten victory for the 29-year-old from Brisbane, a victory which has landed him a spot in the quarterfinals against Novak Djokovic.

Federer has been knocked out of the competition.

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