Canada's Deguchi and Heydarov of Azerbaijan win judo golds at Paris Games
Reigning world champion Heydarov edged French underdog Joan-Benjamin Gaba with a golden score ippon in a marathon final that lasted nine minutes and 24 seconds at Champ-de-Mars Arena.
Heydarov, who earned Azerbaijan its first gold medal of the Games, tried multiple times to catch his breath as the bout wore on and planted a kiss on his opponent's forehead after celebrating victory.
"He did everything to win, I just wanted to show him my respect," said the Kazakhstan-born 27-year-old.
Heydarov, who has now won the Olympic, world and European titles in the space of four months, also announced that he would defend his title in Los Angeles in 2028.
Gaba, ranked 35th in the world and competing in his first Olympics, surprised everyone by fighting his way into the final after defeating London 2012 under-66kg gold medallist Lasha Shavdatuashvili in the round of 32.
After he was finally bowled over by Heydarov, Gaba shared a moment with his family, hugging his brother for a while.
"I have a lot of respect for my opponent in the final, he is very strong and I congratulate him for his victory but I am going back to work in order to win gold in Los Angeles," said Gaba.
France is still waiting for a first gold medal in the Paris judo competition.
Sarah-Leonie Cysique added a bronze medal to the host nation's haul of five medals at Champ-de-Mars Arena after losing to Deguchi in the semi-final.
In the final, Deguchi took out Huh Mi-mi after the South Korean was penalised for a third time.
Deguchi, the 2019 world champion, failed to qualify for the Tokyo Olympics after losing in the semi-finals at the 2021 World Championships.
"Missing Tokyo, these three years felt so long ... I am very happy to bring back the medal and to be honest, to begin with, any colour was fine but winning the gold is very special," said the 28-year-old.
Huh and Canadian Deguchi were both born in Japan. Deguchi, whose mother is Japanese, competed for Japan until 2014, while Huh made the decision to compete for South Korea following the wish of her late grandmother, who was part of Japan's large Korean community.
"She has always been important to me, so I personally believed in her and I really looked up to her and that’s why I chose to be a Korean national," Huh later told a press conference.
Japan was well represented on the podium as Haruka Funakubo claimed the bronze medal in the class, the 100th medal won by the country in Olympic judo.
Her compatriot Soichi Hashimoto later won another bronze for Japan in the men's under 73kg class. Osmanov Adil of Moldova won the other bronze medal final.