The Cliftonville flyweight was put down and out by a late fourth-round bodyshot by reigning champion Cristofer Rosales at Windsor Park on the Carl Frampton v Luke Jackson undecard.
Just two days ago, Ireland’s 21st ever World Champion was crowned in Tokyo, with TJ Doheny claiming the IBF super bantamweight title but Barnes was unable to make it 22 against the impressive Nicaraguan.
Barnes has been out of action since last November when he stopped Elicier Quezada – another Nicaraguan who had also been beaten on a split decision by Rosales the previous March.
Given the opportunity to become Ireland’s quickest pro world champion, Barnes jumped at the opportunity but faced a substantial Latino mountain who defended his belt for the first time.
Facing a larger foe with much more pro seasoning and an eight-year age advantage, Barnes was up against it and was a pre-fight underdog.
The former amateur star would have been keen to dictate the pace and use his superior skill but was unable to stop himself being dragged into a fire-fight by his imposing opponent.
Not fighting his own fight, Barnes still attempted to go toe-to-toe with Rosales and, after losing the opening rounds, was enjoying his best spell of the contest before shipping a soul-sapping bodyshot that instantaneously silenced the Windsor Park crowd.
The size difference was wholly apparent from the opening bell, with Rosale towering over the Irishman who began quickly, looking to raid in and out. The Central American sent out a warning midway through the stanza, driving Barnes back to the ropes and repeating the trick a few moments later. Already Barnes was being forced to set his feet more and trade with Rosales, perhaps an unwise tactic.
Nose bloodied, Barnes attempted to establish the jab in the second but was quickly dragged inside by the thudding bodyshots of Rosales. Much to the crowd’s approval, the pair went hell for leather, Barnes’s work tighter but Rosales having more weight on his shots. With the action cooling, the pair took turns in launching attacks, Barnes getting in and out well at stages mixed with Rosales catching the home favourite at the end of his long, rangey shots.
Momentarily switching southpaw, Rosales drove Barnes back again in the third with a volley of scoring shots before ‘The Leprechaun’ responded by going to the trenches. The busier and bigger Rosales initially was getting the better of the work up close but Barnes ended the session with two stinging left hooks to the body and an eye-catching flurry upstairs.
Barnes enjoyed good success in the fourth but this would all be undone in devastating fashion with one punch. The Belfast boxer boxed well at range for the first minute and was fighting magnificently in the pocket for the second two before shipping a knockout blow.
With just seconds left, a throwing Barnes was caught by a right uppercut to the body that sent him down immediately. In obvious pain, the 31-year-old writhed on the canvas and, as the bell to signal the end of the round chimed, he was unable to even attempt to attempt to get back to his feet.
The devastated Barnes drops to 5(1)-1(1), while Rosales improves his record to 28(19)-3(0)
The double Olympic bronze medalist has been a pro less than two years and, at 31 years old, will no doubt look to rebuild after his attempt to fast-track to a worls title ended in defeat but not disgrace.