Djokovic to face Sinner in blockbuster Shanghai Masters final

Earlier the Italian beat Tomas Machac 6-4, 7-5, ensuring in the process that he will finish the year at the top of the rankings.

Djokovic took a crucial fifth-game break after an unforced error from Fritz to win the first set in 38 minutes.

But the second set lasted twice as long, and was a much more tense affair, as the players sent each other scrambling across the court in a series of thrilling rallies.

The 24-time Grand Slam champion called it an "incredible fight".

"He could have easily won the second set... In the tiebreak it was really anyone's game, (but) I feel like I was never giving up," he said.

In the second set, after the almost 13-minute fifth game eventually held by Fritz, the Serb bent over in exhaustion, breathing heavily.

Fritz missed a chance to take control in the eighth game when he failed to convert a break point, with Djokovic fighting back to hold.

Djokovic, who has been wearing a brace on his right knee throughout the tournament, had to take a medical time-out to see to his left one after the eleventh game.

He continued to look uncomfortable through the tiebreak, skidding over at one point.

But he showed his fighting spirit, coming from 3-5 down to level, before a series of unforced errors on Fritz's part led to him being crowned winner.

Sinner on top

The 23-year-old Sinner has been top of the world rankings since June and after his ruthless semi-final victory will stay there until at least the end of the season, the first Italian to do so.

"It was only a dream just to become number one... Now finishing (the year there) is also a different feeling," the Italian said.

"It's a good feeling. I'm very happy to achieve this. It was an amazing season for me and it's not finished yet," he said, adding that for now he was "focused on tomorrow".

Sinner's meeting with Machac got off to an electric start when the Czech broke in the first game of their semi-final.

The 33rd-ranked Machac was looking to repeat his giant-slaying on Thursday when he knocked out world number two Carlos Alcaraz in straight sets.

But two-time Grand Slam champion Sinner kept his cool to break back in the fourth, then claimed the tenth game to clinch the set.

In the second set neither was able to break serve until the 12th game, when the Italian hit a winner to book his place in Sunday's final.

"It was very tough... he is playing with so much confidence and he can hit a ball really hard, and is serving very well," said Sinner.

"I tried to stay there mentally... I'm very happy about how I'm fighting at the moment."