Jannik Sinner's girlfriend, Laila Hasanovic, was seen supporting the Italian from his box, as he continued making strides at the ATP Finals 2025. The top-ranked player confirmed his relationship with Hasanovic in his victory speech at the Vienna Open.Jannik Sinner has previously dated Italian model Maria Braccini and Russian tennis player Anna Kalinskaya. However, as he stopped appearing in social media posts or being spotted with Kalinskaya earlier this year, fans speculated about their relationship status. The Italian confirmed that he was single during a press conference at the Italian Open in May 2025.Cut to the 2025 Vienna Open, where he trounced Alexander Zverev in the final to win the title, and confirmed he was dating Laila Hasanovic during his victory speech. The 24-year-old thanked his family and "girlfriend" for their support after winning the tournament. He said:To my team, I have to speak in English. Thank you so much for the support. The work you put in, the effort... also to understand me at times is not easy, but thank you for putting in the effort. Everyone here, with family, my girlfriend, friends. To my whole team and also those watching at home. Thank you so much for the support."The Copenhagen-born Danish model and social media influencer recently made an appearance at her boyfriend's box as the latter took the court for title defense at the ATP Finals 2025. In a viral clip, Hasanovic was spotted in Jannik Sinner’s box, showing support for the latter.Sinner previously lost his top rank to Carlos Alcaraz at the US Open, where the latter triumphed. However, by winning the Paris Masters title, he reclaimed his no. 1 position.Jannik Sinner began his ATP Finals campaign with a victory over Felix Auger-AliassimeSinner and Auger-Aliassime at the Nitto ATP Finals 2025 - Day 2 - Source: GettySinner dominantly began his Turin campaign with a win against Felix Auger-Aliassime in straight sets, 7-5, 6-1. It was his 27th victory on indoor hard courts. Winning 85 percent of first serve points and 63 percent of points on his opponent's second serve, he surged past the Canadian in one hour and 40 minutes. Following the victory, Sinner expressed how his focused mentality helped him seal the win in front of his home crowd.“There is a new feeling of playing here, the court is a bit different, so I'm happy with how we've adapted. You have to be focused throughout the match, as soon as you concede a break, it's very difficult to recover. Today, I was very focused. I'm happy, we'll see how the next one goes," he said as seen on the Olympics' official website.Jannik Sinner will next be in contention with Zverev and then Ben Shelton in back-to-back group stages.