Los Angeles: Australia's Lovemore Ndou screamed injustice on Saturday when three American judges gave US southpaw Sharmba Mitchell a unanimous points victory in Atlantic City, New Jersey.
American boxing experts criticised the judges' scorecards, with one describing the lop-sided decision as "perplexing".
Ndou's face had few marks on it after the 12-round bout to decide the International Boxing Federation's interim super-lightweight champion.
Mitchell did not look as healthy. His right eye was swollen, his left was darkened and blood trickled down from his forehead after being battered by the more aggressive Ndou who landed numerous heavy blows throughout the fight.
"Look at me, look at him," Ndou argued after the bout, pointing to the bloodied face of his more-fancied opponent.
"Look at his face look, at my face," said Ndou.
Two experienced boxing writers, including the New York Daily News' Tim Smith, scored the fight a draw while others gave the bout to Mitchell by one or two points.
There was shock in the site of the fight, the grand ballroom at Bally's Hotel and Casino, when the US judges revealed scores that suggested a fight that Mitchell dominated.
Judge Debra Barnes, scoring it 118-110, had Ndou winning just two rounds while Pierre Benoist gave Ndou three rounds in his 117-112 score.
The third official judge, John Stewart, scored it a closer 115-113.
"I did everything," Ndou said, shaking his head. I knew if it went the distance it was his home town. I just feel let down."
Mitchell, from nearby Washington DC, was the short-priced favourite going into the fight and was the IBF's number one contender.
Mitchell was almost even in bookmakers' odds while Ndou was a 6-1 outsider.
Mitchell was scheduled to fight Australia's Kostya Tszyu on Saturday in Russia for the title of undisputed super-lightweight champion of the world.
Tszyu seriously injured his shoulder in Sydney last month while training and had to postpone the fight.
Ndou, born and raised in South Africa but now a resident of Sydney, was the IBF's number nine ranked fighter and was only confirmed as Mitchell's opponent less than two weeks ago.
The 32-year-old Ndou shocked the cocky Mitchell with a strategy of mixing styles during the bout. Ndou began the early rounds fighting an orthodox style, then in the third round switched to the southpaw style.
Mitchell said earlier in the week that he had not watched any videos of Ndou's previous fights and he appeared bamboozled as Ndou switched styles.
Mitchell kept in the bout by firing quick combinations and looking busy, but it was Ndou who landed the heavy blows, hurting Mitchell several times.
There were no knockdowns although Mitchell slipped to the floor twice after the boxers' sweat made the canvas slippery.
Asked after the bout if he'd prepared for Ndou as well as he should, Mitchell replied: "No".
Mitchell said the postponement of the Tszyu fight at such late notice, the death of his grandmother last week and confusion over who his replacement opponent would be were "let-downs".
The 33-year-old American praised the effort of Ndou.
"Lovemore Ndou man, I need fights like that," said Mitchell, who now has a 53 win (29 KO), three loss professional record.
Ndou's record slips to 36 wins (22 KO), six losses and one draw after the defeat.
Mitchell is aiming to take on American and World Boxing Association champion Vivian Harris in the next few months and then plans to meet Tszyu in nine months time when the Australian has recovered from his shoulder surgery.