Nadal, who won the tournament last year, struggled against the sixth-ranked Czech's serve at the start before taking charge in the ninth game. He hit a forehand into the corner to break Berdych and go up 5-4. He won the set with another forehand into the corner.

Nadal cruised to a 4-1 lead in the second, breaking Berdych twice before the 25-year-old Czech took the next two games to make it 4-3. But Berdych's comeback fell short and Nadal closed out the match with a forehand that the Czech returned into the net.

In the final Saturday, the Nadal will face Roger Federer.

He defeated Robin Soderling 6-7 (3), 6-3, 6-3.

In Brisbane, American Andy Roddick will put behind him a season dogged by illness to launch the new year with the defense of his Brisbane International title starting on Sunday.

Roddick, 28, believes he is finally his old self again after fighting a bout of mononucleosis, an infectious viral illness, which restricted him to just two titles in 2010.

The 2003 US Open champion and three-time Wimbledon finalist flew into Brisbane four days before the other tournament top seeds to practice ahead of the new year's first tournament on the road to January's Australian Open in Melbourne.

"I definitely didn't feel well prepared for the last little bit of last year and it showed," Roddick said.

"The one thing that doesn't lie in tennis is if you aren't well prepared, you can't lie about it. It will show one way or the other." Roddick has yet to reach a final at the Australian Open in nine attempts and his Brisbane title 12 months ago was his first tournament win in Australia.

"I've done it a number of different ways and had success different ways, but I like being in the same country and also I like this event," he said. "It's a good place to start the year.

"I felt like I had a pretty good off-season, so I'm excited to start this year fresh. I feel enthused and I'm ready." The eighth-ranked Roddick is one of three top-10 players in the Brisbane draw, with Swedish top seed Robin Soderling and Spaniard Fernando Verdasco also appearing.

"I think it's the first time I've felt 'right' since probably last May. So when you're fit it takes a lot of the mental pressure off because you know you can play any way you want," he said.

Australia's world number six Samantha Stosur is the top seed in the women's draw of the tournament.

Stosur will be challenged by Israel's 13th-ranked Shahar Peer, Russian Nadia Petrova (15) and No.16 Marion Bartoli of France.

"It's great to be in there (top 10) for almost a year, so hopefully I can hold it for a year longer," Stosur said.

"Having made the final of the French Open it makes me believe more that it is possible.

"I love hard court, I grew up playing on hard court I think it's close to my best surface if not my best surface and I play on it all year round."