Decosse, world silver medalist last year, ousted Olympic bronze medalist Claudia Heill of Austria in the first bout to clear the way to the final.
"This is my last competition in 63kg category," she said. "I will upgrade to 70kg class for the next Olympic Games."
The bronze medals were shared by Driulis Gonzalez and Ok Im Won from DPR Korea whose world rank was unavailable for rare appearence in international competition.
The Cuban veteran, 35, who had won three Olympic medals, was golden scored with a koka in overtime by Elisabeth Willeboordse of the Netherlands in the bronze medal competition.
China's Xu Yuhua was outscored by South Korean Ja-Young Kong at her Olympic debut. The 25-year-old Xu made active attacks to the South Korean rival, leading a yuko and a koka. But Xu performed too cautiously in the rest of the time to keep the advantage. She was penaltied for three times for being negative which surrendered a waza-ari loss.
In the men's competition, Ole Bischof from Germany outscored South Korean Kim Jaebum in the final of 81kg-class to win his first Olympic title.
Bischof, 28, managed the only score of yuko to defeat Kim in the five-minute bout that the two had cautiously played. His success also became the second gold medal for Germany at the Games.
"Every game I played today was tough," the German judoka who ranked ninth this year said. "I think the most difficult one was the quarterfinal with Tiago."
Nyamkhuu Damdinsuren of Mongolia seesawed with Roman Gontiuk from Ukraine in the other bronze medal match, both making a waza-ari in the bout. Gontiuk upset Damdinsuren who nearly won the first medal for Mongolia with a yuko later.
The other bronze medal was competed by two world champions, Camilo in 2007, and Elmont in 2005. Camilo won by an ippon.
"This medal doesn't have a color for me. It is as good as gold one." the Brazilian said. "In the toughest moment I fought for the 180 million Brazilian people."
China's Guo Lei was outscored by Montenegro's Srdjan Mrvaljevic after he ipponed Fiderd Vis from Aruba in the first round.
Guo's victory in his Olympic debut also ended the Games tour of Caribbean resort island belonging to the Netherlands who sent only one athlete to the Beijing Olympic Games.
(Xinhua News Agency August 13, 2008)