Chris Eubank Jr finally emerged from his father’s suffocating cloak on Saturday night to send two-time world champion James DeGale hurtling towards retirement and setting his own career on what could be an irresistible upward curve.

“There is no returning for whoever comes out of this defeated,” Eubank said just moments before he walked to the ring, and DeGale agreed. In defeat, the 33-year-old loser equivocated, but said ringside, “I’ve done everything: Olympic gold, two world titles. He was tough, strong. I didn’t do enough. I’ll have to go back and watch it, talk to my team, talk to my family, but I’m pretty sure [about retirement].”

The judges saw it 114-112; 115-112, 117-109, to hand 29-year-old Eubank the IBO’s super-middleweight title, and, while the third score looked unkind, there could be no arguing with the result.

Eubank said, “Now I’m going for all the other belts in the super-middleweight division. I knew he was going to use his boxing ability. I was working on my jab. He’s a very slick southpaw. The game plan worked, smart pressure. I didn’t get too much ahead of myself. I dominated pretty much every single every round. I believe I proved the doubters wrong tonight. They said I was going to get my head jabbed off. It was the most important fight of my career. He didn’t quit, man enough to stay in the ring.”

DeGale, who needed an operation to repair his right shoulder, moved comfortably at the start, his southpaw jab busy and precise, although a trickle of blood at the edge of his left eye encouraged Eubank.

If he sensed a window opening, Eubank went through it straight away. A notoriously slow starter, he was armed now with the fresh instructions of the American Nate Vasquez, and, swarming forward, caught his retreating opponent with a stream of solid head shots to force a count midway through the second round.

The counter-puncher DeGale had been out-counter-punched and resorted to lunging under Eubank’s quicker leads and cocked right hand. “You’ve got to use your feet,” his trainer Jim McDonnell told him before the start of the fourth, and a couple of long lefts – one cutting Eubank’s left eye – got him back in the argument, despite getting caught near the bell.

“Let your hands go,” Vasquez advised Eubank, but his feet did not dance for him to set up the openings and it was the Londoner who worked harder to take the fifth. Eubank’s energy levels rose at the halfway point and he rocked DeGale in centre ring to edge the sixth. Just as he appeared to be falling behind, DeGale came to life in the seventh, only to lose concentration again.

The younger man now looked dominant for longer stretches and the normally elusive Degale was stopping more than his share of punches, although stop-start nature of the contest did not make for a great spectacle.

DeGale poked out his tongue at the end of each round but did not often enough follow the gesture with anything substantial, his contributions speculative single-shot assaults.

By most estimates, DeGale entered the championship rounds in deficit – and the spark remained missing, with his right eye leaking blood again. His balance and judgment had deserted him, replaced by desperation. A left hook disorientated him, and a follow-up salvo cost him another count.

The mission had morphed from grim to forlorn for DeGale. Eubank smelled blood in every way, and stalked his man to good effect before shoulder-charging him to the canvas, which cost him a point in the 11th round. It hardly mattered. His prey was struggling on unreliable legs now, needing a knockout and surely doubting it would come. It didn’t.

Another left rattled DeGale’s teeth in the 12 but pride kept him upright. It was pretty much all he had left at the end.

On an interesting undercard Rio Olympic silver-medallist Joe “Juggernaut” Joyce stopped the (briefly) former world heavyweight title-holder, Bermane Stiverne, in the sixth round to put himself in the frame for a shot at the WBA’s “regular” heavyweight title, owned by Manuel Charr.

A polite athlete who might more appropriately be called Gentleman Joe, Joyce was merciless as he doused the ambitions of the 40-year-old Stiverne, who lasted less than a minute in his previous outing, two Novembers ago against Deontay Wilder.

Joyce and Stiverne sparred in America several years ago and mutual resentment simmered during the week, the visitor boasting that seven months of preparation had brought him to another peak, although entering the ring at a career-heaviest 19st 5lb hardly made him a poster boy for his gym. The argument that mattered was clean and conclusive.

Throwing more punches than a middleweight, Joyce battered Stiverne to a standstill with jabs and crosses that flowed like honey. Down in the third, Stiverne took his licks but looked relieved to be rescued on his feet, mouth open, blood flowing, senses dazzled.

Joyce – who prepared alongside Gennady Golovkin at altitude in Big Bear, California - does not have the one-punch power of Wilder, the pure skill of Tyson Fury or the all-round excellence of his friend, Anthony Joshua, but said ringside, “I’ve sparred them all but Wilder, and I think I’m close to that level.”

He is still raw, and a little robotic, but the Juggernaut has the priceless qualities of determination and self-belief. And, while he will be held in a queue for a little while yet at the highest level, he is capable of taking out the 34-year-old Charr.

Earlier, Lee Selby had to box through a crimson haze for the second time in his career, outpointing Omar Douglas, an uncompromising customer from Wilmington, Delaware, who seemed to think he could use his head as a glove – and, disgracefully, escaped censure.

Selby, moving up two divisions to lightweight, won 116-112, 116-112, 116-114, and ownership of the IBF’s Inter-continental belt insinuates him in discussions for a shot at the federation’s full champion, Richard Commey. Otherwise, he could hunt down Anthony Crolla, whose own late-career ambitions will be tested to the limit in Los Angeles on 12 April against the division’s supreme technician, Vasiliy Lomachenko, who owns the WBA and WBO titles.

On his best nights, of which there have been many, Selby always looked relaxed performing his magic. But his return after losing his IFF featherweight title to Josh Warrington last May was a bloody affair, and he did well to hold his concentration. Sliced badly around his left eye in round two, and late across his right eyebrow, he was a crimson mess at the finish.