World number one Jannik Sinner defeated 24-time Grand Slam champion Novak Djokovic 7-6 (7/4), 6-3 on Sunday to win the Shanghai Masters.

Sinner took a crucial break in the fourth game of the second set to defeat the Serb in 1hr 37min and deny him a 100th career singles title.

"He was just too good today, too strong, too fast," said Djokovic after the match.

Sinner saluted his opponent as a "legend" who kept playing "incredible tennis... year after year."

In a nod to former Djokovic rival Roger Federer, who was watching from the stands, the 23-year-old joked: "There are legends everywhere, I just try to keep up a little bit."

Facing off before an impassioned crowd, neither player blinked in the first set, unable to break the other's serve.

In the tiebreak Sinner quickly took control, breaking Djokovic's serve on the first point and going 5-1 up.

The Serb steadied himself but then netted a volley to bring up set point at 6-3.

Sinner failed to convert initially but didn't miss the second time behind serve.

The next key moment came in the fourth game of the second set, when Sinner was up 40-15 on Djokovic's serve.

Djokovic saved one break point with a fiery ace, but couldn't stop a superb forehand down the line from Sinner that saw him pull ahead.

All that remained was for the Italian to hold his nerve, hitting an ace to finish the match and claim the title.

Sinner's triumph caps off a formidable year, in which he has won two Grand Slams and retained the top spot in the rankings since June.

But it is also a year that has seen him embroiled in controversy after he twice tested positive for a banned steroid in March.

In August, the International Tennis Integrity Agency (ITIA) accepted Sinner's explanation that the drug entered his system unintentionally when his physiotherapist used a spray containing it to treat a cut, then provided massage and sports therapy to the player.

But last month the World Anti-Doping Agency (Wada) said it would appeal the decision to clear him of wrongdoing and was seeking a ban of up to two years.

That news came as Sinner was contesting the China Open, where he lost in the final to Spain's Carlos Alcaraz, who was also watching from the stands on Sunday.

He admitted coming into the Shanghai tournament that he was "not in a situation where I feel comfortable in it." (AFP)