Tennis/Australian Open:They have called him the Djoker, principally because from time to time he has entertained tennis crowds with his mimed imitations of other players, notably Maria Sharapova, the newly crowned Australian Open women's champion. But Novak Djokovic is deadly serious.

He wants to be the world number one and over the last year he has staked his claim with increasing sureness of purpose, culminating in his 4-6, 6-4, 6-3, 7-6 victory over the unseeded Frenchman Jo-Wilfried Tsonga in the men's final.

So for the first time in more than two years Roger Federer and Rafael Nadal have good cause to look over their shoulders.

Djokovic is coming.

It is less than 12 months ago that the Serbian youngster was vying shoulder to shoulder with Andy Murray for a place in the top 10. Djokovic, just one week younger, talked enthusiastically of their joint rise, and how they might spearhead the new generation of youngsters who had the confidence and the ability to challenge for the very top.

They were frequently mentioned in the same breath by commentators and players alike, notably Federer, though he always tended to say nicer things about Murray, just as Pete Sampras used to about Tim Henman.

Federer was a little less generous towards Djokovic, perhaps because the Serb never minced his words, and was always prepared to say that he had the Swiss in his sights.

Here at the Australian Open he beat the world number one for the second time in their last three meetings, and suddenly the plinth that Federer has stood on for three years has begun to show signs of cracks.

Djokovic is now the undisputed world number three, and his victory here may be the beginning of a concerted attack on Federer and Nadal.

"It's not possible one tournament will change history," Djokovic said. "I played amazing tennis here, so I think I absolutely deserved to win, even against Roger in the semi-finals. You know, he accepted in the right way. But for sure, he's going to come back in a big style. He's still planning to be the best player in the world, and we all know how good he is. We are going to see a lot of him, of course, this year." And a lot of me, he might have added.

Murray has a lot of catching up to do. At this time last year both of them reached the last 16 of the Australian Open, Murray making the greater splash after pushing Nadal close. Since then Djokovic has reached the semi-finals at Roland Garros and Wimbledon, lost to Federer in the final of the US Open, and now won his first slam.

Murray continues to be talked of as a possible top-five player, capable of winning a slam. By contrast Djokovic has now done it. He has arrived.

Some remain a little dazed as to precisely how he has rushed up through the rankings so quickly, winning five titles last year, including two Masters Series events, the top titles outside the slams.

He does not play the brand of explosive tennis that so endeared Tsonga to the Melbourne crowds. Neither has he any one particular shot to make you gasp. There is no Sampras serve, or Federer forehand. Rather he does everything to an extremely high standard, and has a tennis brain as acute as anyone's.

In this respect he can get inside his opponent's head, as was apparent when he played an admittedly out-of-form Federer in the semi-finals.

"I love his head," said Martina Navratilova. "He's such a smart guy out there and I like his attitude on and off the court."

It is an attitude, occasionally bordering on the arrogant, that has upset his opponents, although in these days of PR spin and gloss, it is refreshing to have a little needle injected into the proceedings.

He was perhaps unfortunate that the crowd in the Rod Laver arena were very much on the side of Federer and then Tsonga and this clearly rankled with Djokovic.

Coming as he does from Serbia, so often the pariah state, it is not surprising he is a little sensitive, though now he is their champion such matters may change. Perhaps he should take some lessons from another Serb, Ana Ivanovic, who had the fans eating out of her hands.

There is no obvious reason why Serbia has produced a clutch of world-class players.

"I think everybody has been really surprised by the amount of players we have produced from such a small country with no tennis tradition. It's unexplainable, because there was no system whatsoever in our country for tennis and we didn't get much support," said Djokovic.

"But we always had strong support from our parents. And I think this hunger for success and the times and things we went through made us stronger. I think so."

As for Tsonga, he must use his extraordinary success here, which has lifted him into the top 20, to start to impose himself on lesser tournaments and win them.

This was his first singles final on the main tour and the first time in his injury-truncated career that he had won more than three successive matches at tour level.

On his Wimbledon debut last year he reached the last 16, and has the game to do exceptionally well on grass - even reviving serve and volley. What he now needs is a period of injury-free consolidation.

He thrilled many but without a doubt the fortnight belonged to Djokovic.

Guardian Service

Men's singles final

(3) Novak Djokovic (Ser) bt Jo-Wilfried Tsonga (Fra) 4-6, 6-4, 6-3, 7-6 (7-2).

Women's singles final

(5) Maria Sharapova (Rus) bt (4) Ana Ivanovic (Ser) 7-5, 6-3.

Men's doubles final

(8) Jonathan Erlich (Isr) & Andy Ram (Isr) bt (7) Arnaud Clement (Fra) & Michael Llodra (Fra) 7-5, 7-6 (7-4).

Women's doubles final

Alona Bondarenko (Ukr) & Kateryna Bondarenko (Ukr) bt (12) Victoria Azarenka (Blr) & Shahar Peer (Isr) 2-6, 6-1, 6-4.

Mixed doubles final

(5) Tian Tian Sun (Chn) & Nenad Zimonjic (Ser) bt Sania Mirza (Ind) & Mahesh Bhupathi (Ind) 7-6 (7-4), 6-4.