The 35-year-old Djokovic, who had lost his two previous finals at the event, raised his arms out and smiled broadly after sealing the match with an ace.
Djokovic became the oldest champion at the prestigious year-end tournament and also earned the largest payday in tennis history as he walked away with $4.7 million for claiming the ATP Finals trophy undefeated.
It was Ruud’s fourth defeat in a major championship match this year after also losing finals at Miami, Roland Garros and the U.S. Open. Ruud has never won a set against Djokovic in four meetings.
Djokovic started strongly in Turin and had two break points in Ruud’s very first service game. The Norwegian managed to recover although he was also forced to save another break point in the eighth game.
Djokovic finally broke Ruud’s serve at the fourth time of asking. And it was at a crucial moment, on set point, and the Serbian ecstatically pumped his fist in the air after Ruud sent a backhand long.
The seventh-seeded Djokovic broke again in the fourth game of the second set and there was no way back for Ruud.
Djokovic has ended the year with an 18-1 record after winning trophies in Tel Aviv and Astana before reaching the Paris Masters final. His five titles this season also include triumphs at Wimbledon and in Rome.