Joe Joyce fell short in his bid to become Great Britain's 28th and final gold medallist of the Rio Olympics after losing his super-heavyweight final to Tony Yoka at Riocentro.
The ringside judges favoured Yoka's cleaner work over Joyce's strength and aggression by split decision, and the verdict was greeted by a number of boos.
Joyce had been seeking to emulate his former team-mate Anthony Joshua, the London 2012 champion who was watching at ringside.
But Yoka's greater accuracy found the favour of the judges, leaving Joyce with little hope in the last round but to press for an unlikely knockout.
Joyce's style had been derided by Yoka in the build-up to the final, with the Frenchman describing him as a "robot" and questioning his punching power.
The pair had unfinished business after a controversial World Championship semi-final in Doha last year, when Yoka was controversially given the verdict and went on to win the title.
Joyce was the aggressor in the opener, landing first with a nice right hand, and pushing forward looking to squeeze shots through his opponent's tight guard.
The heavier shots continued to come in from the Briton, but Yoka enjoyed persistent success behind his left jab, which was enough to shade it on two of the three judges' cards.
Joyce continued his relentless push forward in the second, with Yoka a little looser and relying more on snaking counter-shots, again catching the judges' eyes.
It effectively meant Joyce needed a knockout to win the last, and despite his best efforts Yoka survived to take the victory on two of the three judges' cards.