Great Britain's Rachel Wilding failed to reach the semi-finals of the 78kg Olympic judo competition.
The 28-year-old from Surrey, who beat Spain's Esther San Miguel to reach the quarter-finals, lost by ippon to Ukrainian Anastasiia Matrosova.
Noriko Anno, Japan's four-times world champion, finally won her first Olympic gold by beating China's Liu Xia.
Ihar Makarau of Belarus won the gold in the men's 100kg, defeating South Korea's Jang Sung-Ho in the final.
Anno, who lost in the first round of the 1996 and 2000 Olympics, was leading by a penalty score when, 22 seconds from the end, she punished her opponent's reckless charge forward by despatching her with a sode-tsuri-komi-goshi.
Her gold medal was a sixth for Japan in Athens, a record haul for a single Games for one country in judo.
Japan's Kosei Inoue, widely regarded as one of the best judokas of all time, suffered a shock exit in the men's 100kg quarter-finals.
The reigning Olympic champion and four-times world champion lost by ippon to Holland's Elco van der Geest in what was his first international defeat.
Ariel Zeevi delighted a large Israeli contingent in the crowd by landing a bronze medal when he threw van der Geest for ippon.
Germany's Michael Jurack also claimed bronze against Movlud Miraliyev of Azerbaijan.
Italy's Lucia Morico beat Anastaysia Matrosova of Ukraine and Cuba's Yurisel Laborde beat Celine Lebrun of France to win the women's bronze medals.