Jannik Sinner has secured the year-end world No.1 ranking at the Shanghai Masters and will be out to celebrate the landmark by winning a mouth-watering final with Novak Djokovic.

Sinner beat Czech Tomas Machac 6-4 7-5 in the semi-finals on Saturday, as he became the first Italian to attain the honour of being top at the end of the year.

Then Djokovic moved a step closer to his 100th ATP title when he beat American seventh seed Taylor Fritz 6-4 7-6 (8-6) to set up the clash everyone had wanted to see.

Fourth seed Djokovic played some dazzling tennis as he stretched his remarkable head-to-head record against Fritz to 10-0.

But amid his brilliant performance, he sustained a hip issue that required treatment on court.

Djokovic, the 24-time grand slam champion, will play his fifth final in the tournament's history as he looks to nail his century of wins and a fifth Shanghai Masters crown.

Earlier, Machac had made a promising start against Sinner by winning the opening two games before the Italian got on the board, with the top seed then closing out a hard-fought first set in 44 minutes after errors flew from the 30th-seeded Czech's racket.

Sinner was made to work hard by Machac, even more so in the second set, but the Italian proved too solid for his fellow 23-year-old as he sealed his 64th win of the year while making just nine unforced errors.

The Italian's dominant season has seen him win his first Grand Slam at the Australian Open and another at the U.S. Open.

"It's amazing. It's something you dream of when you're a kid, when you're young. Just to reach the number one spot, now but to have the year-end ... it's also a different and special feeling," Sinner said.

"I think we all saw how much talent and firepower he (Machac) has. I had to be very, very careful in every service game."

Sinner can win his seventh trophy of the year on Sunday.