'I'm the happiest man on earth!': 20yo Tsitsipas shocks champion Federer at Aus Open (PHOTOS)

'I'm the happiest man on earth!': 20yo Tsitsipas shocks champion Federer at Aus Open (PHOTOS)
Australian Open champion Roger Federer has suffered a shock defeat to Stefanos Tsitsipas, who at just 20 years old is 17 years his junior, to become the first Greek player ever to reach the quarter finals of a Grand Slam.

There was no Greek tragedy for world number 15 Tsitsipas, who served up a classic performance against the 6-time Australian Open winner and 20-time major winner 6-7, 7-6, 7-5, 7-6, on Sunday in Melbourne to book his place in the last eight. 

"There's nothing I can describe it to, I'm the happiest man on earth right now, I can't describe it," an overwhelmed Tsitsipas told John McEnroe in his post-match interview.

'I'm the happiest man on earth!': 20yo Tsitsipas shocks champion Federer at Aus Open (PHOTOS)

Tsitsipas' reward for squeezing past veteran Federer at Rod Laver Arena is a date with Andy Murray-conquerer Roberto Bautista Agut in the quarter-final on Tuesday. 

For Swiss legend Federer, he failed to make the final eight of the tournament for only the second time in 16 years of his remarkable tennis career.

Tsitsipas had to endure a grueling 3 hours and 45 minutes to see off Federer, finally forcing the 37-year-old former long-reigning world number one into a backhand error after lumping a forehand long to leave Tsitsipas serving for the match in the fourth-set tie-break.

Upon winning, Athens-born Tsitsipas dropped his racket and seemed to incredulously mouth "me?" to his team before weeping while walking over to them to celebrate.

After the match, Federer praised his young opponent: "It definitely didn’t go the way I was hoping on the break points. I also didn’t break him at the Hopman Cup so clearly something is going wrong."

The Australian Open served up another surprise earlier in the day when Russian tennis star Maria Sharapova crashed out of the tournament to 22-year-old local favorite Ashleigh Barty, but not before enduring the wrath of the crowd due to perceived dirty tactics.