Andreas Seppi caused the biggest upset of the 2015 Australian Open Friday.

In a stunning performance, World No. 46 Seppi recorded one of his greatest victories to knock out second seed and four-time former champion Roger Federer 6-4, 7-6(5), 4-6, 7-6(5) for a place in the fourth round.

“To beat Roger first time, especially in a Grand Slam, best-of-five, is a special moment for me,” said Seppi. “Of course, at the beginning, I just went on the court to enjoy the match and to play my best tennis… I was pretty calm. I have to say, from the beginning [and] also in the important moments.”

It ended a 10-match losing streak against Federer, who saw his run of 11 straight semi-final appearances at Melbourne Park come to an end. Federer last lost in the Australian Open third round in 2001 (l. to Clement).

“[It was] just a bad day,” admitted Federer. “I wish I could have played better, but clearly it was tough losing the first two. [I] had chances to get back into it. I let it slip, I mean, both times in some ways. I guess I won the wrong points out there today. I knew how important that second set tie-break was, so clearly that hurt, losing that one. The end wasn't pretty. It wasn't easy to play with the shadow. But it was the same for both of us. [It was] just a disappointing loss.”

I didn't believe it first.

Originally Posted by Tex

I didn't believe it first.

I am a Huge fan of Roger Federer..But this is how it goes in sport..By catching a bad day..