However, that would be as good as it got for Ruud, who is making his ATP Finals debut, as Djokovic rallied to take the first set to a tie break. From there, it only looked like there would be one winner.The second set proved an altogether more lopsided affair, with Djokovic stamping his authority on the contest and eventually prevailing in one hour and 30 minutes.READ: Novak Djokovic secures year-end No. 1 spot for record seventh time, surpassing Pete SamprasThe win moves Djokovic onto 39 career victories at the ATP Tour Finals, tying Ivan Lendl for joint-second place. Roger Federer remains way out in front with a remarkable 59 career wins.Djokovic, who recently secured a record seventh year-end world No. 1 ranking, hasn’t won the ATP Finals title since 2015, despite being arguably the most dominant player on the circuit in that time.The 34-year-old came closest to matching Federer’s record of six ATP Finals titles in 2018, when he lost in the final to this year’s No. 3 seed Alexander Zverev.While Djokovic and Ruud may be at opposite ends of their careers, the 22-year-old is already showing signs that he could be one of the vaunted next generation that will carry the torch from tennis’ old guard.Ruud secured an impressive five ATP titles in 2021 to become the first Norwegian player to qualify for the prestigious year-end ATP Finals, which pits the world’s top eight against each other in a round robin format before advancing to a knockout stage.Earlier this year, Ruud won three ATP titles in as many weeks, becoming the first man since Andy Murray in 2011 to achieve that feat.The youngster showed impressive resilience against Djokovic on Monday, notably holding serve in a brutal game to take the first set to a tie break, but is still searching for his first hard court win over a top 10 player.Next up for Djokovic will be the winner of Monday evening’s match between Stefanos Tsitsipas and Andrey Rublev.