The other favourites fell by the wayside except world champion Choi Min-ho of South Korea who fought back from a quarter-final defeat to take bronze against Iran's Masoud Hajiakhondzadeh.
The man who ended Choi's gold medal hopes, Mongolia's Khashbaatar Tsagaanbaatar, joined him on the podium after edging out Spain's Kenji Uematsu.
Tani becomes first woman to win twice
Greek judoka dies
Japan's Ryoko Tani won her second Olympic judo title on Saturday -- the first woman to achieve the feat.
The diminutive fighter, dubbed the "Pocket Rocket", beat France's Frederique Jossinet in the under 48kg competition.
Tani, with six successive world titles behind her, is making her last appearance at the Games.
She was a raw 16-year-old when beaten by France's Cecile Nowak in the 1992 Olympic final.
Germany's Julia Matijass dashed Greek hopes of a home medal by defeating Maria Karagiannopoulou with an inner thigh throw to take the bronze.
China's Feng Gao snatched a joint bronze, beating European champion Alina Dumitru of Romania.
French crisis after barren Games
Japan fight to record medal tally