Team GB's Anthony Ogogo has to settle for a bronze medal following his defeat to Brazil's Esquiva Falcao Florentino.
The first round was a tight affair, with neither man landing anything particularly clean.
Ogogo was getting the better of the second round, putting together a few nice combinations. However, Falcao also began to land in the last 30 seconds.
The judges felt that the Brazilian had done enough to establish a three-point lead ahead of the decider.
The Brit pressed forward straight from the third bell, but was on the business end of a good shot to bring about a standing count.
Falcao tasted blood and went in for the kill, raining in a string of powerful shots to force Ogogo down, resulting in another standing count.
Ogogo's exertions had taken their toll and he was struggling to hang on. Falcao coasted to victory in the latter stage of the round when Ogogo had given his all.
The judges gave the Brazilian a 16-9 victory.