China's Xie Siyi won his second diving gold of Tokyo 2020 - by beating the team-mate with whom he won his first.
World champion Xie, 25, won the 3m springboard gold with a final score of 558.75, finishing ahead of compatriot Wang Zongyuan, who scored 534.90.
Wang and Xie won the 3m synchro gold together last Wednesday.
Xie was told he would never dive again after breaking an ankle in 2014, and missed Rio 2016 after the injury caused issues and required further surgery.
But he recovered to win 3m springboard world championship gold in 2017 and 2019 - also earning 3m synchro world gold with Cao Yuan in Gwangju two years ago.
He was pushed all the way for Olympic springboard gold, though, as Wang scored 102.6 points with his final dive, a superb forward four-and-a-half somersault effort.
However, Xie equalled it with an excellent effort of his own, matching Wang's final-round score to maintain his lead and ensure victory.
Britain's Jack Laugher took the bronze medal with 518.00 points.