This Saturday, before an anticipated 40,000-strong crowd at Cowboys Stadium in Dallas, Texas, the Derry Destroyer hopes to add another Mexican scalp to his name in the ominously named Michael "Murder Man" Medina.
Seemingly back to his vintage best after reuniting with trainer Harry Keitt, Duddy, who at age 30 is seven years older than Medina, is the decided favorite in the scheduled ten-rounder.
Despite an impressive 22-1-2 ledger with 18 KOs - the same number of stoppages as the 28-1 Duddy -- Medina has not faced the same quality opposition as the Irishman.
While Duddy's victims have included such respected pugs as Campas, an ex-world titlist, Freddie Cuevas; Anthony Bonsante and Howard Eastman, Medina counts five debutants and seven other journeymen with losing records on his list of conquests.
Like most fighters from across the Rio Grande, Medina turned pro early, a month shy of his 19th birthday in June 2005. Although moving up from 154 pounds where he holds the Mexican title, he's not far removed from his apprenticeship and in Duddy faces an unmovable object who's been a scourge to Mexican fighters.
"I think the Mexican style of fighting brings the best out of me," Duddy shrugged last Sunday when asked to explain his dominance over the Mexicans he's faced.
Joked Keitt: "It may be because he [Duddy] has some Mexican mixed with his Irish," before offering a more plausible reason.
"John is a fighter and comes to fight. Like I say, you don't get paid for overtime in the ring. He sparred with a Mexican named Flores for this fight and he was bringing it and John was figuring it out.
"Whatever Medina brings, John will figure it out, whether it be body shots, uppercuts, he'll figure it out."
Duddy was happy with his form heading to Dallas on Tuesday and declared himself ready to go ten rounds if possible. "We're ready to go the whole haul; we're always prepared for the worst scenario," he said.
"It's going to be a great stage, the whole world will be watching and I'm looking forward to it," he added.
"It's a definite 'W' [win]," Keitt assured. He's in tip top shape and ready to go."
A win will put Duddy, who's ranked 12th by the World Boxing Organization, back in strong contention for a world title shot.
The Duddy-Medina bout is available on HBO pay per view on the Manny Pacquiao-Joshua Clottey welterweight match. The first televised bout is scheduled for 9 pm.