World No 1 Jannik Sinner overcame a slow start to book his place in the <a href="https://www.thenationalnews.com/tags/us-open/" target="_blank">US Open</a> second round, before admitting he has received a mixed reaction from fellow players following his failed anti-doping tests controversy. Sinner, 23, was playing his first match since he escaped a provisional suspension after two failed tests earlier this year. The Italian was <a href="https://www.thenationalnews.com/sport/tennis/2024/08/21/jannik-sinners-failed-test-saga-splits-opinion-and-dominates-build-up-to-us-open/" target="_blank">cleared of fault or negligence</a> by an independent tribunal and has defended himself stoutly amid criticism he was shown favouritism with the speed in which his case was resolved. It initially looked like the drama had taken its toll as American Mackenzie McDonald won the first set and then had a break of serve in the second, but Sinner assumed control and earned a 2-6, 6-2, 6-1, 6-2 victory inside Arthur Ashe Stadium. “I was curious to see how the reaction of the fans has been, but it has been very positive,” he said. “I was very glad how the support was, also playing against an American, it’s a little bit different. “So I’m happy [with] how I handled those situations, it was not easy. I think a lot of positive things from today, and so let’s keep seeing what’s coming in the next round. “There are some reactions from other players. I cannot really control what they think. You know, that’s how everything went and how it was. I cannot control the players’ reaction, and if I have something to say to someone, I go there privately, because I’m this kind of person. Overall, it has been not bad. So I’m happy about that.” Elsewhere in the men's draw, former champion Daniil Medvedev booked his place in the second round with a 6-3, 3-6, 6-3, 6-1 win over Dusan Lajovic. Novak Djokovic, seeking a record 25th Grand Slam title, beat Radu Albot 6-2, 6-2, 6-4. Stefanos Tsitsipas became the highest seed to be knocked out after losing to Australian Thanasi Kokkinakis in four sets. Felix Auger-Aliassiame, seeded 19th, also lost. Third seed and 2022 champion <a href="https://www.thenationalnews.com/tags/carlos-alcaraz/" target="_blank">Carlos Alcaraz</a> began his campaign with a four-set win over Australian Li Tu, who returned to the sport after six years away. The 21-year-old Spaniard did not have it all his way on Arthur Ashe, losing the second set in a 6-2 4-6 6-3 6-1 win. “The second set I made 18 unforced errors. So that was the huge difference for me," he said. “He started to play better. That’s obviously serving better, playing more aggressive, and not making a lot of mistakes. “I’m really happy to get through and get a chance to be better [in] the next round. Obviously, I felt well on court. I think I hit the ball well. I moved well.” Two-time champion Naomi Osaka made a triumphant, tearful return to the US Open, beating 10th-seeded Latvian Jelena Ostapenko 6-3, 6-2 a year after wondering if she would be back. Japan's Osaka missed last year's US Open after giving birth to her daughter Shai, and the former world No 1 is still trying to kick her return to the sport into top gear. But she was dialed in against 2017 French Open champion Ostapenko, firing 19 winners to wrap up the victory in just 63 minutes. Osaka took the court in a bouncy tulle skirt and bow-bedecked jacket -- shedding both to play in a ruffly green dress, the outfit a nod to "Japanese and Harjuku culture," she said. "I was trying not to cry when I was walking out," Osaka said, tearing up during her post-match on-court interview. "Last year I was watching Coco [Gauff] play and I so badly wanted to step on these courts again," she said. "I didn't know if I could ... just to win this match and just to be in this atmosphere means so much to me." It was Osaka's first win over a top-10 player in four years. She has made two quarter-finals at tour events in 2024 but has yet to progress beyond the second round at the majors. None of the other three, she said, stirs her like the US Open. "It's like a combination of a lot of different things," said Osaka, who next faces Czech Karolina Muchova. "I grew up here, so just seeing kids, and then remembering my daughter, but seeing kids coming and watching me play and just remembering that I was a kid ... made me very emotional. "Just seeing the stadium really full, it meant a lot, because I was, like, 'Oh, I hope people come watch me play." World No 1 and 2022 champion Iga Swiatek defeated 104th-ranked Kamilla Rakhimova after having to save three set points in the second set. French Open champion Swiatek, chasing a second New York title to add to her four triumphs in Paris, saw off the Russian lucky loser 6-4, 7-6 to extend her season-leading record to 54 match wins. However, it was an unconvincing display by the Pole who committed 41 unforced errors. There was a defeat for another former champion, however, as 2021 winner Emma Raducanu went down 6-1, 3-6, 6-4 to Sofia Kenin.