Two-time US Open champion Naomi Osaka was spotted watching Jannik Sinner take on Felix Auger-Aliassime at the Arthur Ashe Stadium in the US Open semifinal. The two players have split the first two sets with Sinner holding a 5-2 lead in the third set at the time of writing.Osaka arrived there in a chic brown outfit and is fresh off losing her own US Open semifinal clash against Amanda Anisimova on Thursday. The Tennis Letter shared the video of Osaka, with the following caption:"Naomi Osaka is in the house watching Jannik Sinner and Felix Auger Aliassime at the U.S. Open. 2-time champion. Semifinalist this year. Can’t get enough of this sport. ❤️"Osaka also shared that she was attending the match at Arthur Ashe Stadium through her Instagram stories. She posted a wide angle snapshot from where she was seated to watch the clash between Sinner and Auger-Aliassime.Osaka's Instagram storySince becoming a mother in July 2023, Osaka had her best outing at the US Open this year. She has previously won the tournament two times in 2018 and 2020.Naomi Osaka keeps an "inspired" attitude after losing her first Grand Slam semifinalIt may be surprising to believe at first, but before this year's US Open, Naomi Osaka had never lost a Grand Slam semifinal clash. Her spirited run in the 2025 US Open came to an end on Thursday after Amanda Anisimova took the Japanese down, in a dramatic 6-7 (4), 7-6 (3), 6-3 match.This marked her deepest Grand Slam run since winning the Australian Open in 2021. After the match, Osaka kept an "inspired" attitude with hopes of trying to get better with each and every tournament."Honestly I don't feel sad," Osaka said. "It's really weird. Well, it's not weird, because I just feel like I did the best that I could. Honestly, it's kind of inspiring for me, because it makes me just want to train and try to get better, and hopefully just give it my very best shot again and see what happens. But I think I can't be mad or upset at myself."Osaka further added that she is proud of her efforts and is appreciating the hard work she is doing behind the scenes. She added:"Just knowing that I love the sport. I want to play matches. I want to play in Arthur Ashe Stadium and do whatever it takes to get there. I think just willing to accept the grind for me is something that I worked really hard on."It remains to be seen if there is a Grand Slam title waiting for Naomi Osaka when she gets to Melbourne next year, to compete at the Australian Open.