South African Tatjana Schoenmaker smashed the long-standing women's 200m breaststroke world record Thursday to win the Olympic gold medal.
The 24-year-old timed 2min 18.95sec to better the 2:19.11 set by Denmark's Rikke Moller Pedersen in 2013.
America's Lilly King was second in 2:19.92 with her team-mate and training partner Annie Lazor third in 2:20.84.
The 24-year-old Schoenmaker, who won silver in the 100m event, had signalled her intent by going close to the record in the heats and she made no mistake in the final.
King went out fast and turned first at both the 50m and 100m mark before Schoenmaker made her move, reeling in the American to touch first.
It made her the first female South African to win an Olympic swimming gold since 1996, when Penny Heyns swept the women's 100 and 200 breaststroke.
Despite missing gold, it was an improvement for King who placed 12th at the Rio Olympics.
It was the third world record in the Tokyo pool, but the first individual one after Australia's women set a new mark in the 4x100m relay and China did the same in the women's 4x200m relay.
Australia's Emma McKeon wins women's Olympic 100m freestyle
Australian sprint star Emma McKeon blazed to the women's 100m freestyle Olympic gold medal in the second fastest time ever on Friday.
The 27-year-old set a new Olympic record of 51.96 seconds ahead of Hong Kong's Siobhan Haughey (52.27) and fellow Australian Cate Campbell (52.52).
Russia's Evgeny Rylov wins men's Olympic 200m backstroke gold medal
Russian two-time world champion Evgeny Rylov scored the Olympic backstroke double Friday by winning the 200m gold medal to go with his 100m title.
He touched in a new Olympic record time of 1min 53.27sec ahead of defending champion Ryan Murphy of the United States (1:54.15) and Britain's Luke Greenbank (1:54.72).
China's Wang Shun wins men's Olympic 200m individual medley
China's Wang Shun claimed the men's 200m individual medley gold medal, the event's first new Olympic champion since 2000 after the retirement of four-time winner Michael Phelps.
He touched in 1min 55.00secs ahead of Britain's Duncan Scott (1:55.28) and Switzerland's Jeremy Desplanches (1:56.17).