Djokovic overcomes Fritz to book spot in final
Novak Djokovic sealed his place in the final of the season-ending ATP Finals after edging past Taylor Fritz 7-6 (7-5) 7-6 (8-6) in Turin.
The Serbian, who is bidding to equal Roger Federer's record of six ATP Finals titles, overcame Daniil Medvedev in a bruising three-hour contest on Friday, and he was again made to work hard for victory against spirited American Fritz.
Djokovic struck first in the opening set with a break to love in the fifth game, yet Fritz responded immediately to level at 3-3.
A tiebreaker was needed to separate them with Djokovic's superb forehand winner sealing the first set in style.
Fritz broke Djokovic in the opening game of the second set but a simple missed backhand allowed his opponent to break back and make it 5-5.
That set the stage for a high-quality tiebreaker which Djokovic ultimately won to claim victory in one hour and 54 minutes.
"I had to fight to survive," Djokovic said in his on-court post-match interview.
"I didn't feel very reactive today or very comfortable.
"I knew coming into today's match from yesterday's gruelling battle against Medvedev it would take me some time to adjust and find the dynamic movement I need against Fritz, who is one of the best servers on the tour.
"I am very pleased to have overcome this one as I don't think it was one of my best days with my tennis but I managed to hang in there."
Should Djokovic beat Casper Ruud in the final he will claim the largest pay day in tennis history, $4,740,300 ($A7,097,400) for sealing the trophy undefeated.
Norwegian Ruud advanced to a showdown with Djokovic by dispatching Andrey Rublev 6-2 6-4 in the second semi-final.