DUBAI (AFP) - Novak Djokovic won his fifth title in six tournaments and extended an unbeaten run to 18 matches as he clinched a fourth Dubai Open title with a 7-5, 6-3 win over Tomas Berdych on Saturday.

The world number one from Serbia underlined his pre-eminence in the world game with an athletically aggressive performance against the world number six from the Czech Republic, who knocked out Roger Federer, the titleholder, in the semi-finals.

Berdych had chances to take control of the first set after making the first break of serve, but missed three chances to consolidate it, and also narrowly failed to convert three crucial break points in the following game.

These moments suggested that the biggest difference between the two men is a mental one, something indicated again near the end when Djokovic coped with a time violation warning from the umpire as he was serving for the match.

Djokovic was clearly delighted to triumph in his first tournament since successfully defending the Australian Open title five weeks ago.

"To prevail like this and to be the last one standing is thrilling for me," he said of his 36th career title.

"It was a very close match and could have gone either way. It was never going to be an easy final because Tomas is a fantastic player. He's been on the tour a long time and is very experienced.

"He beat Federer in an incredible match," Djokovic added, referring to the three match points Berdych saved while halting the Grand Slam record-holder.

Djokovic also believes that his victory on Dubai's fast courts will stand him in good stead with the year's opening Masters event getting underway at Indian Wells next week.

"I haven't always been the player who loves to play on the fast, super-fast surfaces (like this one), but I'm happy because during the week I can also work on my aggressivity, coming into the net, using my serve better," he said.

"That's what I have done in this tournament and in particular over the years. I have been trying to work on a few things that can give me more variety in the game, and I can use that in the tournaments to come." Djokovic's success on Saturday was also due to tactical prowess.

At times he provoked errors by subtlely making Berdych generate his own pace, and then increased his own pace or counter-attacked at well-timed moments.

There were certainly moments when it seemed that Berdych, a player sometimes troubled by tension, might get himself far enough in front to relax into overdrive.

He made the first break at 2-3, and having lost it in a game of four deuces, almost got another when he chiselled out three break points in the ninth game.

Had he converted any of these Berdych would have been serving for the set, but he missed his best chance at 30-40, with a forehand pulled wide, while Djokovic typically played two fine rallies on the others.

Djokovic also hung tough in the crises. Berdych, by contrast, was occasionally at his most fallible when it mattered most.

He allowed Djokovic's break back for 4-4 after sneaking himself into a great position to make a stolen volley, only to miss the shot. Then when he was serving to save the set at 5-6 he played his worst game of the match.

The second set hinged on a break at a psychologically damaging time.

When Djokovic steepled up an enormous, but short lob and Berdych hammered it wide, it put the favourite 5-3 ahead and gave the underdog little time to repair the damage.

Although Berdych did get a break back point at 30-40, courtesy of a rare Djokovic double fault, the world number one played close to his best in four of the next five rallies, closing the match out.

"I gave everything yesterday and didn't have enough today," said Berdych.

"And Novak deserved to win.

"Let's see how long this guy is going to be around here. I will try to work hard and come back and try to fight for the win."