MELBOURNE (AP):

Roger Federer will look back on it and wonder, just as he did on court, why he watched as Andreas Seppi went down the line and ended his streak of reaching the Australian Open semi-finals for 11 consecutive years.

The 17-time Grand Slam champion was facing match point against Seppi for the first time in their 11 head-to-head meetings, and had control of the rally when he hit a deep forehand into the corner and followed it to the net.

The number 46-ranked Seppi lunged to his right and stuck out his racket, more hopeful than confident, and guided the ball down the line. Federer let it go past, and glanced back to see it land inside the baseline, giving Seppi a 6-4, 7-6 (5), 4-6, 7-6 (5) win and a spot in the fourth round.

Federer had reached the semi-finals or better at Melbourne Park ever since winning the first of his four Australian titles in 2004. He hadn't been ousted before the fourth round here since 2001. That changed in an instant.

"I don't know. Ask him how he felt hitting it," Federer said. "It's clearly a big blow, because I actually hit my forehand pretty good."

Andy Murray hasn't had a match on the centre court at Melbourne yet this year, but it hasn't bothered the three-time finalist. He won in straights sets again, beating Joao Sousa 6-1, 6-1, 7-5 to set up a clash with number 10, Grigor Dimitrov, who laboured through a five-set win over 2006 Australian Open finalist Marcos Baghdatis.

Seventh-seeded Tomas Berdych needed eight match points before beating Viktor Troicki 6-4, 6-3, 6-4 and will next play Bernard Tomic, who beat fellow Australian Sam Groth 6-4, 7-6 (8), 6-3.

After having to fend off match points in her previous match, Maria Sharapova made sure it wasn't even close in the third round by beating Zarina Diyas 6-1, 6-1 in 61 minutes.