Peng's whereabouts became a matter of international concern following a nearly three-week public absence after she posted a message on social media in early November, alleging that China's former Vice-Premier Zhang Gaoli had sexually assaulted her.
Speaking after the game, Medvedev paid tribute to Djokovic, saying, " "What you accomplished this year and throughout your career, I have never said this to anybody, but, for me, you are the greatest tennis player in history.
The 18-year-old ended her scarcely believable run in New York with a 6-4 ,6-3 win over her 19-year-old Canadian opponent in a high-quality final.
After Osaka lost her serve again to end the match by hitting a cross-court backhand wide, she shook hands with Vondrousova at the net, walked to her chair, zipped her racket up in her bag and followed Vondrousova off the court.
23-time Grand Slam singles champion Serena Williams to skip Tokyo Olympics
Djokovic, who previously won at Roland Garros in 2016, has become the first man to win all four Grand Slams twice since the fully professional Open era began in 1968.
Both women had worked hard to get to the main stage at Roland-Garros.
Djokovic's victory extended his advantage in the head-to-head with Nadal, having claimed his 30th win in their men's record 58th meeting.
