Novak Djokovic has overcome injury to become Serbia's first Grand Slam singles champion, claiming the Australian Open men's crown with a four-set win over Jo-Wilfried Tsonga at Melbourne Park.

Having not dropped a set en route to the final, the world No.3 had to do it the hard way, firstly rallying from a set down and then also battling a hamstring strain that he suffered early in the fourth set to beat unseeded Frenchman Tsonga 4-6 6-4 6-3 7-6 (7-2).

With Djokovic's movement restricted after he sustained the injury, the decider looked headed for a fifth set for the first time since Melbourne Park's first men's final 20 years ago when Mats Wilander beat Pat Cash.

But while Tsonga tried hard throughout, he was unable to capitalise on Djokovic's ailment despite enjoying more support from the packed centre-court crowd, with the 20-year-old Belgrade native digging deep to capture the Norman Brookes Challenge Cup.

Both players began the match nervously, with Tsonga dropping his serve after his opening salvo went long by about a metre, only for Djokovic to likewise surrender his own first service game.

Both players came close to dropping their serves again, firstly Djokovic in the fourth game and then Tsonga in the fifth, before Tsonga served three straight aces to hold in the ninth game and then broke in the 10th to win the set with a forehand winner and then a lob.

Games went with serve early in the second set until the seventh game when a couple of errors from the Frenchman and then a reflex, defensive return from Djokovic for a winner led to the break that eventually gave Djokovic the set.

With Tsonga's unforced errors piling up Djokovic upped the ante with another break in the third game of the third set and then finally broke again in the ninth game after Tsonga had saved six set points.

The momentum looked to have changed early in the fourth set though when Djokovic injured himself stretching for a volley, and he called for treatment while leading 3-2.

With Djokovic trying to keep the points shorter in an attempt to win the match in four sets, Tsonga was nonetheless unable to make the most of the changed circumstances as his own weariness kicked in.

The set eventually went to a tie-breaker after Tsonga held in the 12th game soon after calling for the crowd to make some noise, but it was Djokovic who raced away with it by winning five of the first six points and he fell to his back in delight when he sealed victory.

Men's Australian Open champion Novak Djokovic has spoken of his relief at breaking through for his maiden Grand Slam title after his four-set win over Jo-Wilfried Tsonga at Rod Laver Arena.

While he is only 20, Djokovic had desperately wanted to take his chance to open his Grand Slam account having made the semi-finals or better at the past three tournaments. Having realised one of the best moments of his career, Djokovic said he felt a weight had been lifted off his shoulders.

"It's an indescribable feeling, something that I always dreamed of, of course. I think every player dreams about winning a Grand Slam. It's something special. It's a special event. It's two weeks long, all the best players in the world playing. Then you come up in the end as a champion, you know, only one guy to win the tournament. I mean, I'm still not aware of the big achievement I have had in these two weeks," he said.

Djokovic revealed that he felt under enormous pressure coming into the final as favourite, having defeated Roger Federer in the semi-finals.

"It was kind of strange feeling to get into the match as the favourite. As I was saying in the pre-conference, it's always dangerous to play against the underdog, the player who doesn't have really anything to lose," he said.

"You get to the final, you know, final match, you just want to make another step and win it. I was nervous and there was pressure, and I think it's understandable. But I'm very happy the way I deal with that pressure," he said.

Djokovic hasn't had time to consider whether his success ushers in a new era in men's tennis after breaking the duopoly of Roger Federer and Rafael Nadal.

"I mean, it's not possible that only one tournament is changing the history. Of course, I mean, I played amazing tennis here, so I think I absolutely deserved to win, even against him (Federer) in the semifinals," he said.

"I'm gonna take it easy, you know. I'm not gonna try to think about reaching even higher goals right away. I'm not in a rush. I want to enjoy in my success and just celebrate with the people I care about. From then, I'll see what it goes."

The past three years have been dominated by the Swiss and the Spaniard, with no other player able to claim a Grand Slam title since Marat Safin at Australian Open 2005. Djokovic, the poster child of the new generation, believes the Swiss master and the determined Spaniard will fight as hard as ever.

"Everybody who wins a Grand Slam, you have to give them a lot of appreciation and respect. I just felt it now, what it feels like. Hopefully, you know, in the future I'm gonna feel it more," he said.

"He's (Federer) gonna come back in a big style, of course. He's still planning to be the best player in the world, so we all know how good he is. We're gonna see a lot of him this year."

Djokovic becomes the first player from his proud sporting nation to claim a Grand Slam title, inspiring the local Serbian community into fanatical support for the 20-year-old from Belgrade. There are 30,000 people of Serbian origin in Melbourne, and each and every one of them was behind their man as he overcame injury and a first set slip-up to secure victory. The thought of those fans, plus all the people back in Serbia, puts a smile on the proud young man's face.

"I think everybody was really surprised with the amount of the players we produced from such a small country with no tennis tradition. So I think it's still unexplainable, because there was no system whatsoever in our country for tennis and we didn't get so much support needed in that stage, mostly needed," he said.

"We've always had I can say strong support from our closest family, from our parents. And I think this hunger for success and the times and things we went through made us stronger."

With plenty of strength both in the women's and men's game at the moment, Djokovic believes that Serbian tennis could well be set for a golden era.

Tsonga proud despite defeat