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He reached the Wimbledon final -- taking the world No. 1 Novak Djokovic to five sets -- and ended the campaign by helping Switzerland to a maiden Davis Cup title.

But did all the tennis last year cost Federer -- and his 33-year-old body -- at the Australian Open this year?

Was it a hand injury that he sustained earlier this week? Or was his opponent simply too good?

No matter what the potential reasons, the end result is that Federer will have to wait for a record-extending 18th grand slam title after he lost to Andreas Seppi 6-4 7-6 (5) 4-6 7-6 (5) in the third round in Melbourne on Friday.

There were no such troubles for Rafael Nadal, Andy Murray and Maria Sharapova.

That Seppi was the man who knocked out Federer was a surprise -- in their 10 previous matches, the Italian had never won. He had claimed just one set.

And against tennis' big three of Federer, Djokovic and Nadal, Seppi owned a dismal 1-25 record.

But the world No. 46 played one of his best matches, crucially not crumbling when the finish line was in sight.

Instead it was Federer who blinked in the fourth-set tiebreak.

He led 3-1 only to double fault at 3-2. Then leading 5-4, Federer made a costly backhand unforced error. Federer rued missed opportunities in the second set tiebreak, too, when Seppi was there for the taking.

"It just broke me to lose that second set," Federer told reporters. "And actually the fourth, I should win it, too. Just a brutal couple of sets to lose there."

Seppi completed the upset in stunning fashion, scrambling before hitting an instinctive forehand passing shot winner down the line.

"For sure it was one of the important shots of my life," said Seppi.

Federer thus exited, despite winning more points in the match overall, 145 to 144.

"I felt for some reason yesterday and this morning it was not going to be very simple today," Federer said. "Even in practice I still felt the same way.

"I was just hoping it was one of those feelings you sometimes have and it's totally not true and you just come out and you play a routine match. I was aware of the test and was well prepared.

"Just somehow couldn't play my best tennis today. It was definitely partially because of Andreas playing very well."

Perhaps the warning signs were there from his previous round.

Federer lost a set in the second round to Seppi's fellow Italian, Simone Bolelli. He -- and this is rare for Federer -- called for the trainer to address an issue with his hand. Federer thought he might have been stung by a bee.

He didn't mention the hand or any other physical issue in his briefing with reporters.

Federer also defended his decision to play exhibition matches in India in December during tennis' notoriously short off-season.

"I wanted to go to India," said Federer. "I wanted to go back to Switzerland for Christmas. I practiced as hard as I possibly could.

"Can't do more than that. Sure, the year ended late, but one week later than normal. At the end of the day, honestly I'm confident that what I did was the right thing."

Federer's exit means Murray's path to the semifinals has become significantly easier. The two-time grand slam champion and Federer were, on paper, due to meet in the quarterfinals.

While Federer was sent packing, Murray easily dispatched Portugal's Joao Sousa 6-1 6-1 7-5.

Murray's performance wasn't the only topic of conversation during his press conference, though. A particular tweet was mentioned, too.

After Nadal visibly struggled on court in the second round and was close to vomiting in his five-set victory over Tim Smyczek, Murray appeared to criticize the Spaniard in this tweet: "When I cramped and won in the us open last year I was a 'drama Queen, unfit, needs to see a shrink, faker' weird..." Murray wrote.

But he insisted Friday he wasn't targeting Nadal.

"I didn't watch the whole match the other night, but clearly Rafa was struggling pretty badly," Murray said. "It was a great effort to come through it, which rightly is what everyone was saying.

"But that certainly wasn't the case at the U.S. Open when I was in a similar state. And yeah, I just don't understand why that would be the case."

Nadal looked better physically on court after suffering from cramps against Smyczek, eliminating Israel's Dudi Sela 6-1 6-0 7-5 under the lights in Rod Laver Arena. He saved all seven break points he faced -- and they all came in the third set.

He said in an on-court interview that he slept a lot in a bid to recover but didn't budge when asked for a percentage of how he felt physically.

"Uh, I was never very good in mathematics," Nadal joked.

Nadal and Murray were joined in the fourth round by seventh-seed Tomas Berdych and 10th-seed Grigor Dimitrov.

Dimitrov survived Marcos Baghdatis' upset bid, edging the charismatic 2006 finalist 4-6 6-3 3-6 6-3 6-3.

Second-seed Sharapova, Dimitrov's girlfriend, swept aside 31st-seed Zarina Diyas 6-1 6-1 two days after saving match points against a Russian qualifier.

Other winners in the women's draw included third-seed Simona Halep and seventh-seed Eugenie Bouchard.

Read: Serena clicks into gear