World number one Novak Djokovic won the Dubai Tennis Championships for the first time since 2013 with a straight-set win over Stefanos Tsitsipas.

The 32-year-old Serb, who extends his winning streak to 21 matches, clinched his fifth Dubai title with a 6-3 6-4 win over the Greek second seed.

After a tight start, Djokovic broke for 5-3 with a wonderful cross-court backhand winner and held for the set.

He served out for victory after another decisive break for 5-4 in the second.

Djokovic had been calm on court throughout the week, often meditating in his chair on the changeovers, but roared with emotion as he celebrated winning his 79th career title.

"It was very close even though it was a straight-set win," said Djokovic, who also won the Dubai titles in 2009, 2010, 2011 and 2013.

"I was fortunate to hold my serve at the start of the match."

Djokovic has been in fine form in the first two months of the season, winning all of his matches as Serbia triumphed at the inaugural ATP Cup and then claiming a record-extending eighth Australian Open title.

A three-week break from competition after Melbourne had the desired effect for the 16-time Grand Slam champion.

Djokovic did not drop a set in his opening four matches in Dubai and when he was finally tested against France's Gael Monfils in Friday's semi-finals, came back from a set down and fought off three match points in the second-set tie-break.

Once he moved a set and a break up against 21-year-old Tsitsipas, it looked to be another formality.

Tsitsipas, who was aiming for back-to-back titles after winning last week's Marseille Open, looked to be tiring as Djokovic broke for 3-2, only for the Greek to instantly level.

But it proved to be a false dawn as Djokovic refocused to break again and then clinch victory on the first of three championship points with a backhand winner.

"Yesterday I was one shot away from losing the match when three match points down and it could have easily happened I was not here. That is sport - things can turnaround quickly, said Djokovic.

"I have played really well in most of the matches. This is a big win for me."