Justin Murphy, McMillan's opponent at the Broadway Theatre in Barking, did not do a great deal of thumping, but it was not for want of trying. Beneath a veneer of ring rust - this was McMillan's first fight for many months - the speed of thought, foot and hand which once saw him hailed as one of the finest talents Britain has produced was as compelling as ever. Nor was there the faintest hint of the shoulder injury which had cost him the world crown four years earlier, a problem now cured by an American surgeon.
Murphy was finally stopped after four and a half rounds in which punches had landed from every angle, and his attempts to respond had found their target long gone. McMillan was in a different league to the other seven fighters on Tuesday's card, and he was the reason that 600 spectators had filled the Broadway almost to its capacity. It is all the more astonishing, then, that McMillan left the ring without a penny to show for his efforts.
Those whose sport is their living are generally as reluctant as any other worker to do their job for nothing. When the sport in question is boxing, it is all but unheard of, but for McMillan there was no clearer way to register his frustration at being unable to secure a match worthy of his talents.
"It was a big decision and I wasn't over-keen," he says, "but I'd be walking along the street and people would say: 'What are you doing now'? I've been training for seven months and it's soul-destroying when there's no goal. It had got to the point where I had to fight."
But why for nothing, in a small-time venue and a pitiful audience on a cable television channel? "Boxing is as much politics as merit," Jonathan Rendall, McMillan's agent, said. "The ratings are manipulated by the big promoters. Some people get there on merit, but others get manipulated to a high position because the promoters have large amounts of money invested. Colin is self-managed, he's not attached to a big promoters, and he's been frozen out."
And this is a fighter who won a Lonsdale belt in record time, whose injured shoulder gave way in only the second round against Steve Robinson, yetMcMillan lost the points decision only narrowly despite effectively completing the rest of the fight with just one hand. Nigel Benn admits to studying videos of his fights for tips.
McMillan's reluctance to sign over his soul to a promoter does not endear him to the power-brokers, but he is no dewy-eyed idealist. "I don't mind being exploited," he said. "That's the nature of the game. But there's limits to how much you want to be exploited to get a title shot. I've still got a certain belief about how good I am."
The ultimate title shot for any featherweight at present is against Naseem Hamed, but a meeting between the flashy Prince and McMillan, the supreme stylist, remains a distant prospect. "I'm sure Hamed thinks he can beat Colin," Rendall said, "but he must also think that there are other people he can beat more easily. And, for a fight like that, you'll be taking a very small percentage of the purse, which is fine, Colin's the challenger and he needs the chance, but you'll also have to sign yourself away for the rest of your career in the event that you do beat him. That wouldn't be tolerated in any other sphere."
And so it is that a sport which could do with some good publicity just now can allow one of its most intelligent and elegant practitioners to fight for free in obscurity. The British Boxing Board of Control, meanwhile, believes that Peter Harris is the No 1 challenger for the British featherweight title. In his latest fight, Harris was knocked down four times and stopped in the third.
Lesser men might buckle under the frustration, but McMillan takes succour from the examples set by Benn and Frank Bruno. "It takes a lot of mental strength to believe in yourself and prove everybody wrong, but I know what I wanted to achieve and when I won the world title that was just the first step. Unfortunately the shoulder injury threw everything out of sync.
"Now I'm going to pick myself up and get on with it. That's the fighter in me."