Italian Jannik Sinner made a flying start in the ATP Finals in Turin on Sunday by beating Stefanos Tsitsipas in straight sets, 6-4, 6-4. The 22-year-old laid down a marker in the first match of the ATP's season-ending showpiece event in front of a delighted home crowd in Italy's northeast. Despite trailing his opponent 5-2 in their head-to-head record, Sinner got into an early lead in the first set when he broke at 2-2 and then never looked back as he confidently saw out victory in one hour 25 minutes. The encounter stayed on serve until the fifth game of the first set, when the fourth seed sprang to break the Greek's serve, needing only one break point to move into the lead he would never relinquish. Tsitsipas applied pressure on the Italian's serve in the very next game, forcing it to deuce, but Sinner held on to consolidate the break, before serving out the first set to claim it 6-4. First on serve again in the second set, the Greek world number six was immediately behind the match when Sinner broke his service to lead 1-0, with Tsitsipas struggling to live with the speed of the Italian's groundstrokes. At 2-0, Sinner forced three break points, but was unable to convert as Tsitsipas doggedly stayed in the match. Playing on home turf and now a set and a break up, Sinner really relaxed into the second ATP Finals event of his career and never looked troubled on his serve as he methodically ticked off the games to claim a straight-sets victory. “The match went really, really well and the crowd support was crazy,” Sinner said on court as fans chanted his name. “It's not just about improvement, it's about destinations and the destination I wanted to reach this year was to be here. “It was a long week before coming here and I was excited to finally step on court. I knew it would be tough but I think I answered the questions really well. "It's a special week, such an incredible feeling playing here with the roof closed and the crowd." In the second match of the Green Group in the round-robin stage on Sunday, top seed <a href="https://www.thenationalnews.com/sport/tennis/2023/11/05/novak-djokovic-defeats-grigor-dimitrov-for-record-extending-seventh-paris-masters-title/" target="_blank">Novak Djokovic</a> was due to face Denmark's Holger Rune. Djokovic can seal the year-ending number one spot with a single win in the Finals. Matches in the red group on Monday feature Carlos Alcaraz v Alexander Zverev and Daniil Medvedev v Andrey Rublev. The top two finishers in each group advance to the semi-finals.