TOKYO -- Naomi Osaka is back playing tennis, still winning and also talking to the media again.
The Japanese superstar who lit the Olympic cauldron defeated 52nd-ranked Zheng Saisai of China 6-1, 6-4 on Sunday at the Tokyo Games in her first match in nearly two months.
Osaka hadn't played since she withdrew from the French Open in May to take a mental health break, revealing that she has dealt with depression. She then sat out Wimbledon.
Osaka stopped to talk with reporters after Sunday's match, having said in Paris that she experiences "huge waves of anxiety" before meeting with the media and that she would be skipping news conferences.
"More than anything else, I'm just focused on playing tennis," Osaka said. "The Olympics has been a dream of mine since I was a kid, so I feel like the break that I took was very needed. I feel definitely a little bit refreshed, and I'm happy again."
She added that she was "happy" that reporters were asking her questions, then said: "I feel a little bit out of my body right now."
"There's nothing wrong with my body; I just felt really nervous," Osaka said. "I haven't played since France, so there were definitely some things that I did a bit wrong, but I think I can improve in the matches that I continue playing."
The second-ranked Osaka was sharp from the start, serving an ace down the T on the opening point of the match and racing out to a 5-0 lead.
Wearing a bright red dress and a red visor and with her hair styled in red-and-white braids to match the colors of the Japanese flag stitched onto the left side of her chest, Osaka served six aces in all and produced 25 winners to Zheng's 10.
Osaka's match was originally scheduled to open the tournament Saturday but then was pushed back a day before her starring role in Friday's opening ceremony.
"I feel very, very proud," Osaka said, revealing that Olympic organizers asked her to handle the cauldron honors back in March.
"When I lit the flame, I was super honored," she added. "I think that's a position that you dream about and not anyone can do it. So, for me, when they asked me if I wanted to, I was very surprised but very honored. And I'm just very happy to be here and very happy to play -- especially in Tokyo."
Osaka will next face 50th-ranked Viktorija Golubic of Switzerland.
On a good day for the host country, 2016 bronze medalist Kei Nishikori beat fifth-seeded Andrey Rublev 6-3, 6-4.
For other top players in the tennis tournament at the Tokyo Games, it wasn't so straightforward.
Top-ranked Ashleigh Barty was upset by 48th-ranked Spanish opponent Sara Sorribes Tormo 6-4, 6-3, and two-time defending gold medalist Andy Murray withdrew from singles because of a right quad strain.
Both still remain in the doubles competition.
Heat and humidity were issues again, with the temperature rising to 91 degrees and the sun baking the hard courts at Ariake Tennis Park.
Also advancing was Wimbledon finalist Karolina Pliskova of the Czech Republic, No. 3 Aryna Sabalenka of Belarus, No. 4 Elina Svitolina of Ukraine, No. 7 Garbine Muguruza of Spain and No. 10 Petra Kvitova of the Czech Republic.
Carla Suarez Navarro, the Spaniard who plans to retire this year, beat Ons Jabeur of Tunisia 6-4, 6-1 for her first victory since recovering from Hodgkin's Lymphoma.
Camila Giorgi of Italy eliminated Jennifer Brady, the American who was this year's Australian Open finalist, 6-3, 6-2.
Among the men advancing were third-seeded Stefanos Tsitsipas of Greece, No. 4 Alexander Zverev of Germany, No. 7 Hubert Hurkacz of Poland, No. 8 Diego Schwartzman of Argentina, No. 12 Karen Khachanov of ROC and Max Purcell of Australia -- who took Murray's spot in the draw and defeated Felix Auger-Aliassime 6-4, 7-6 (2).
The Associated Press contributed to this report.