Little fancied American Tor Hamer won the Prizefighter International Heavyweights crown at a packed York Hall after he upset heavy favourite Kevin Johnson on points in the final.
The fighter from New York scored a unanimous decision in the final as he outworked his vastly more experienced opponent as the judges scored the fight 30-27 29-28 and 30-28 in his favour.
In an all-American final it was expected that Johnson would have to much experience and power for the much smaller Hamer who looked more like a cruiserweight.
However, Hamer proved to be too quick and elusive in the final as 'Kingpin' failed to fire behind his jab after a night in which he had claimed he was destined to be the next heavyweight champion.
Earlier in the night Hamer had beaten Tom Dallas in less than a minute as the referee was forced to step in, but much had been taken out of the Brit after a gruelling stoppage victory over Tom Little in the quarter-finals.
Johnson's route was perhaps more comfortable as he beat the inexperienced Noureddine Meddoune with a first round stoppage, before winning a split decision against fellow world title contender Albert Sosnowski.
Hamer will now hope to be propelled to the world stage after the victory, much as Audley Harrison was able to do after winning the Prizefighter tournament and securing a date against David Haye.