Cuba's Idalys Ortiz, bronze medalist four years ago, won the women's Olympic +78kg category judo title on Friday.
Ortiz, 22 and world number six, beat Japan's Mika Sugimoto in the final after she was awarded the win by the referee and two judges as the fight finished scoreless after extra time.
There was also a second medal in two days for the host nation when British outsider Karina Bryant, competing in her fourth Olympics, won bronze.
Veteran Bryant, 33, put in a convincing display to beat Iryna Kindzerska of Ukraine to the delight of the crowd at London's ExCel Centre.
China's Tong Wen beat Brazil's Maria Suelen Altheman for the other bronze.
(Reporting by Michael Holden; Editing by Alison Williams)
(This story corrects the weight category)