Took some time, but Federer eventually played like Federer

— -- MELBOURNE, Australia -- Scratchy, grouchy and out of sync. That was Roger Federer in the early stages against Tomas Berdych on Wednesday night at the Australian Open. Nothing was going Fed's way.

For the first time in this year's event, Federer, who is trying to defend his title at the age of 36, was off-kilter, struggling for his usual fluency. Trailing 5-3 in the first set, a challenge that didn't go his way had him irritated. Really mad, in fact. He barked with the chair umpire for a few moments before lumbering back to his side of the court.

Here's where the story changes. In a matter of what seemed like a split-moment, Federer morphed into Federer, and Berdych, well, he became the Berdych we all know. Poor guy.

Berdych hadn't beaten Federer in five years, and that wasn't going to change. Federer saved two set points in the opener and ripped through the tiebreaker 7-1, cruising to a 7-6 (1), 6-3, 6-4 victory and setting up a semifinal Friday against unseeded Hyeon Chung of South Korea.

"I hung around, got a bit lucky, a bit angry, a frustrated, maybe at the umpire, but I actually thought the call was good anyway," Federer said. "I was just frustrated and a bit antsy. I'm happy I got out of that first set. It ended up being key to the match. Tomas was great."

Tomas was great, but he lost. As he has done now in 14 of 20 meetings with Federer. And just the sight of Berdych across the net probably made Federer feel good. It was his third-round win over the Czech here last year that gave him, for the first time, the belief that he may be able to go all the way after returning to the court for the first time in six months. Seeing Berdych again must have been a comforting experience, even if Federer knows more than most how dangerous he can be.

Berdych has not beaten Federer since 2013, and it is easy to forget that this is a man who has given the Swiss real trouble in the past. Berdych stunned him in the first round of the Olympics in 2004, beat him at Wimbledon in 2010 and at the US Open in 2012. But ever since, Federer has dominated the rivalry.

Berdych has been a solid player for a long time. From 2010 to 2016, he finished inside the top 10 for seven straight years, only dropping out last year. His free-flowing groundstrokes and effortless power can make anyone look slow.

Ultimately, Federer won in 2 hours, 14 minutes, the longest match he has played these two weeks.

How did he mount the comeback? By serving better. When Federer trailed 5-2 in the opening set, he had won just 14 percent of points on his second serve. By the time the match finished, he'd lifted that to 53 percent. Once his serve, which also yielded 15 aces, slipped into gear, the rest of his game followed, and Berdych, for all his effort, found himself in a familiar spot.

With Rafael Nadal gone, limping out of his quarterfinal against Marin Cilic on Tuesday night with an upper-leg injury, Federer is, of course, the heavy favorite to win the title. Compared to last year, when he had to battle through a tough five-setter in the quarterfinals against Kei Nishikori, Federer should be fresh when he plays Chung, who will have the pressure of a first Grand Slam semifinal to deal with.

Everyone expects him to take care of Chung in the semis en route to Slam No. 20. But could there be a complacency problem that lies ahead? And what about nerves? Federer admitted being nervous at the beginning of his match against Berdych, and alluded to the fact that the same could be true against Chung.

"You don't want to think too far ahead, what if, what if, because I feel that's exactly the moment when you stumble," Federer said. "That's why I think I was actually very nervous going into this match tonight, and that's why I struggled very early on. I knew the danger of Berdych. Seeing what has happened to so many other top seeds here in the draw, I was a bit wary going into tonight."

Federer praised Chung's movement, comparing it to Djokovic's, which is the ultimate compliment. Federer has never played the Korean before, but he has two days to prepare, which he'll need. Because unlike Berdych, Chung has no history of failing against Federer.

Of course, he has no history of beating him, either.