TOKYO: Japan’s Naomi Osaka won in straight sets on her highly-anticipated return to the court at the Tokyo Olympics on Sunday, while world number one Ashleigh Barty crashed out in the first round. Osaka, the star of the opening ceremony, defeated China’s Zheng Saisai 6-1, 6-4 and said she felt “refreshed” after taking an eight-week break for mental health reasons. The Australian Open champion had not played since May, when she walked out of Roland Garros saying that media commitments were harming her mental health. Osaka showed few signs of rust as she reeled off the opening five games on the Ariake Coliseum centre court, which likely would have been packed to capacity if not for a spectator ban because of coronavirus restrictions. The second seed broke the 52nd-ranked Zheng for a 2-1 lead in the second set and closed out an 87-minute victory on her third match point. The 23-year-old Osaka is attempting to become Japan’s first Olympic tennis champion. She will play Switzerland’s Viktorija Golubic in the last 32. Osaka is now the clear favourite for gold after Barty, the reigning Wimbledon champion, dropped serve twice in each set and made 55 unforced errors in a 6-4, 6-3 loss to Spain’s 48th-ranked Sara Sorribes Tormo. Sorribes Tormo will go on to face France’s Fiona Ferro in the second round. French Open runner-up Stefanos Tsitsipas battled past German veteran Philipp Kohlschreiber 6-3, 3-6, 6-3, while Alexander Zverev defeated Taiwan’s Lu Yen-hsun 6-1, 6-3 inside an hour. Kei Nishikori, the 2016 bronze medallist, took down Russian fifth seed Andrey Rublev 6-3, 6-4, and is the only one of four Japanese men to make round two. Karolina Pliskova, the Wimbledon runner-up two weeks ago, demolished France’s Alize Cornet 6-1, 6-3, while Aryna Sabalenka, the third seed from Belarus, swept past Pole Magda Linette 6-2, 6-1. Newly-weds Elina Svitolina and Gael Monfils, who tied the knot just before flying to Tokyo, suffered contrasting fortunes on their Olympic honeymoon. Svitolina overcame Laura Siegemund 6-3, 5-7, 6-4 in a match that lasted more than three hours, but Monfils lost to Ilya Ivashka of Belarus.