Novak Djokovic brushes off rumours as he finds magic touch

It is a sign of the sceptical climate created by Lance Armstrong that when Novak Djokovic came off the court on Tuesday, having confirmed his place in the semi-finals, the questions were less about the smoothness of his backhand than how he could -possibly maintain such a mind-boggling level of fitness.

Only two days previously, Djokovic had been pushed to the edge in a 5hr 2min battle with Stan Wawrinka. Yet here he was, gambolling around the baseline like a faun and chasing down any number of apparently unreachable balls. Nobody asked him if he was popping any magic pills, but they might as well have done.

Faced with this potentially awkward situation, Djokovic responded like the dignified diplomat he had become, rather than the young scamp who would once have hit out angrily at the first sign of suspicion.

"People who don't know tennis, who have never been in those kinds of situations, would not truly understand what the player has to go through," he said. "Not just when you prepare for a grand slam, but also during a grand slam. After five hours of a match, you need to really put a lot of time into recovery. As I said, I understand that many people have many different views and opinions, and I respect that. But I'm doing everything that is legal, that is correct, that is natural, and it's working well."

Djokovic's ability to regroup contrasted with that of Gilles Simon, the Frenchman who was so wiped out by his 4hr 43min contest with Gael Monfils on Saturday night that he might as well have brought an armchair on to the court for his Tuesday afternoon meeting with Andy Murray.

But then Djokovic was described by his defeated opponent, Tomas Berdych, as "probably the fittest guy on tour right now". And this was hardly the first time we had seen him bounce back like some human elastic band, because the same thing happened in Melbourne 12 months ago. Then, he outlasted Murray over the course of nearly five hours on the Friday night, before taking down Rafael Nadal in the longest grand slam final ever played - the tennis equivalent of War And Peace. His four-set, 151-minute canter against Berdych yesterday must have felt like a mere novella by comparison.

Murray and Nadal are both capable of stunning feats of endurance in their own right, yet you feel they pay a higher price for their efforts. Djokovic is so light and flexible, his body just seems to soak up the pounding impacts of hard-court tennis like a giant shock absorber. If he had not been a tennis player, you feel he could have made it as a gymnast. His coach, Marian Vajda, tells a story of how Andre Agassi's jaw dropped when he saw Djokovic's stretching routine before an exhibition match in 2006.

"Novak had his legs like this, one on the ground and the other on the shoulder of the physio," Vajda recalled. "Agassi said: 'What you doing, guys? What is this? You're going to break your leg'. Novak says: 'No, this is normal for me.' 'Really'? Agassi said. 'This is normal for me.' He was so stiff he couldn't even bend over."

That ability to stretch out and get low to the ground allows Djokovic to hunt down more balls than anyone else on the tour, and certainly many more than Murray, who carries far greater muscle bulk and describes himself as "the least flexible person". But then he probably has not seen Agassi in a while.

Yesterday Djokovic's retrieving was at its bewildering best as he made Berdych, one of the most authoritative hitters in tennis, earn each point two or three times over. It was all too much for the Czech, who has never reached the semi-finals of this event. "This was a chance for me," he said, "but I didn't come up with my best game and that's what was -decisive."

Berdych still contributed to an entertaining spectacle in Rod Laver Arena. He may have made a clumsy start, allowing Djokovic to romp through the first set, but he snared the second with a barrage of huge serves and clumping forehands.

After that, though, Djokovic found a rare rhythm as he swept to a 6-1, 4-6, 6-1, 6-4 victory. It is hard not to feel that he has survived his cliffhanger moment, when Wawrinka virtually held a pistol to his temple but could not quite manage to pull the trigger. Like the hero in a Saturday serial, he could well be headed for a triumphant conclusion.

Speaking after the match, Berdych certainly gave the impression that the rest of the field had missed their best chance to eliminate the world No?1. "He's going to really appreciate the time he will get now to rest. And then he's going to be very strong again."

As for Djokovic, he admitted that "I felt good enough today to go another five hours". No one doubted him.