MELBOURNE (Reuters) - No tennis for four months, no problem for Rafa Nadal.

Tennis - Australian Open - Semi-final - Melbourne Park, Melbourne, Australia, January 24, 2019. Spain's Rafael Nadal celebrates after winning the match against Greece's Stefanos Tsitsipas. REUTERS/Aly Song

Only weeks after worrying that his Australian Open might be in jeopardy, the Spaniard charged into his fifth Melbourne final with a 6-2 6-4 6-0 demolition of 20-year-old Stefanos Tsitsipas on Thursday.

Nadal has waged near-constant war with his body over the course of his career, winning and losing his share of battles with an injury count that nearly dwarfs his 17 Grand Slam trophies.

He played no matches after retiring from last year’s U.S. Open semi-finals with a knee problem but the hurt continued with an abdominal strain and surgery on his ankle surgery which soured the end of his 2018 season.

A thigh issue then forced him to pull out of the Brisbane International earlier this month, leaving him doubtful and bereft of match fitness when he arrived at the first major of 2019.

However, after six matches in Melbourne, Nadal has not dropped a set, and is back to his free-wheeling, forehand-whipping best, as Tsitsipas found in a harrowing one hour and 46 minutes.

“I was a little bit worried, of course, because there has been issue after issue,” 2009 champion Nadal told reporters of his nervous tournament lead-up.

“I was worried about having another issue. But in terms of tennis, I know I was playing well.

“Then, of course, you have to compete. After four, five months without action at all, then of course you know that you can come here and anything can happen, no?

“It’s not easy to be back after four months, five months, and play the way I am playing.

“Of course, I didn’t expect that at all.”

Tsitsipas, Greece’s first Grand Slam semi-finalist and the man who toppled double defending champion Roger Federer, was also surprised by the Spaniard, who will play either top seed Novak Djokovic or Frenchman Lucas Pouille for the title.

The Greek was broken in the third game and another five times for the match as a marauding Nadal bounded around the court like a hyperactive teenager, instead of a banged-up 32-year-old with a history of health insurance claims.

NEW SERVE

Eighteen years after turning professional, Nadal continues to add new tricks and he credited his remodeled serve for allowing him to be more aggressive against Tsitsipas and the other young pretenders he smashed in straight sets.

“I can’t play like Roger (Federer) when I don’t have the serve of Roger,” said Nadal, who crushed American 21-year-old Frances Tiafoe in the previous round.

“But today I’m serving better. That’s why I’m able to create more winners on the first ball.”

With a second Melbourne title on Sunday, Nadal can become just the third man to win all the Grand Slams twice after Australians Rod Laver and Roy Emerson.

It would re-open the debate about the greatest men’s player of all-time, even with Federer on 20 Grand Slam titles.

“The results say during my career I did a lot of things very well,” said Nadal.

“Today I have to adapt my game to the new time and to my age, that’s all.

“That’s the only reason why at this moment I am still here competing at a high level.”