MELBOURNE: 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.

The world number one was given a thorough workout by the 18-year-old Tomic during an absorbing third-round clash as he maintained his bid to become only the third man, and the first since 1969, to hold all four grand slam titles at once.

“My body is still not perfect,” Nadal told reporters after the two and a half hour tussle under the floodlights on a packed Rod Laver Arena. “I am sweating more than usual. I am more tired than usual when I'm playing. I don't know what's going on. I'm doing all that I can.”

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.”

TOMIC ONSLAUGHT

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.

Sweat-soaked red T-shirt clinging to his body, Nadal came roaring back and finally took the second set 7-5 with a fierce serve down the middle.

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.”