The 22-year-old Japanese player was the fifth-seeded player in the tournament and is Japan's top-ranked woman at No. 62. She prefers to play on hard courts but has adapted to the heat and clay in Rio.
Zakopalova won two WTA titles 10 years ago, but has now lost 12 consecutive singles finals. In parts of the match she seemed unwell, probably bothered by the 32 degree (90F) heat and intense humidity.
In the men's final, top-seeded and No. 1 Rafael Nadal of Spain faced Alexandr Dolgopolov of Ukraine. Nadal is 297-21 on clay, the best record in the Open Era.