WASHINGTON (AP) - Mike Tyson's career apparently ended in yet another shocker Saturday night when he quit on the stool after taking a beating in a foul-filled sixth round against unheralded Kevin McBride. Tyson lost for the third time in his last four fights, and once again he faded badly as the rounds went on, before deliberately head butting McBride in a desperate attempt to end the fight in the sixth round. "I don't have the stomach for this anymore," Tyson said. "I most likely won't fight anymore. I'm not going to disrespect the sport by losing to this caliber of fighters." Tyson was out of gas when he was pushed to the canvas as the sixth round ended, his head stuck between the first and second ropes. He stayed there for several seconds before finally untangling himself from the ropes and wobbling back to his corner. When referee Joe Cortez came by to look at him, his corner told Cortez the fighter could not continue. Cortez then went over and raised McBride's hand in victory, while he still sat on his stool. Tyson, meanwhile, just sat on his stool blankly watching McBride's celebration, a white towel draped over his shoulder. When he got up to congratulate his opponent, McBride kissed him on the left cheek. "I could have gone on but I thought I was getting beat," Tyson said. "I don't think I have it anymore." Tyson was winning, ahead 57-55 on two scorecards and behind by the same score on a third. But the fight had clearly changed and McBride had taken over and it only figured to get uglier as it went on. The Associated Press had the fight even, 56-56. The 38 year-old Tyson was a huge favourite over McBride and won the early rounds. But as the fight went on, it was McBride landing the bigger punches, as Tyson desperately tried to score a knockout. Tyson was weary by the fifth round and, in the sixth round, he was penalised two points for deliberately head butting McBride and opening a cut over his left eye. The head butt came after Tyson appeared to try to break McBride's arm in a clinch, like he once did against Francois Botha, and after he hit him with several low blows. Cortez warned Tyson after he grabbed McBride's arm, telling him "I don't want any more fighting with the arms, understand?" When the action resumed, Tyson then head-butted McBride, forcing Cortez to stop the fight briefly to allow McBride to recover and to penalise Tyson. In a career filled with tremendous highs and terrible lows, Tyson may have reached a new low in the loss to McBride, an Irish journeyman who came into the fight with no credentials. Tyson (50-6) was a shell of the fighter he once was, throwing wild punches and trying to knock out McBride with each shot. But McBride (33-4-1) took the punches and came back with some of his own and Tyson gradually began wearing down. The sixth round was bizarre even by the standards of a fighter once banned from boxing for biting Evander Holyfield's ear. Tyson was clearly exhausted and opened the round by throwing wild shots. He then appeared to try to break McBride's arm, drawing a protest from the Irish fighter. Tyson wasn't through. He banged his bald head against McBride, prompting Cortez to take two points from him for the foul. Tyson was paid $5 million for the fight, which was on the low-end of purses he has made in his career. After his creditors got $2 million, the IRS got its cut and his ex-wife got $750,000, so there wasn't much left for the fighter. Reprinted from jamaicaobserver.com