By Alastair Himmer

MELBOURNE (Reuters) - Questions remained over Rafa Nadal's health after he said he was still feeling the effects of a flu bug during a 6-2 7-5 6-3 victory over local hope Bernard Tomic at the Australian Open on Saturday.

Nadal, the champion here in 2009, recovered from 4-0 down in the second set to regain control of the match just when Tomic was threatening an uncomfortable night for the Mallorcan.

"I didn't play well tonight," he said. "I played short.

"I have to play closer to the lines. But even if I didn't play my best, for me to win in three sets is a very positive result for me.

"It's more important to win matches when you are not playing your best than when you are playing your best. It's more difficult and has more value.

"I have to play better if I want to get to the quarter-finals."


Nadal bombed through the first set, but Tomic came out swinging in the second, bursting into a 4-0 lead as the Spaniard suddenly appeared powerless against the youngster's onslaught.

A break at the start of the third set effectively ended Tomic's resistance and Nadal closed out proceedings with a drilled backhand crosscourt that his opponent struck wearily into the tramlines.

Nadal, who next faces Croatia's Marin Cilic, can join Don Budge (1938) and Rod Laver (1962 and 1969) as the only men to hold all four majors simultaneously if he wins his second Australian Open.

Tomic admitted he had been taken to school by the world's best player and could see little wrong with Nadal's fitness.

"I thought (the second set) was over at 4-0," he said, shrugging. "Against these guys, especially in the top 10, you can't afford to lose concentration.

"Physical-wise he's a machine. He just wears you down. He's a true champion. The only way to beat him is step up and hit the ball hard, go for your shots.

"If you rally with him a lot, he's going to drain you out. He's too fast, too quick."

(Editing by Martyn Herman)