The home camp were claiming a technical draw, insisting that the cut had been caused by a head- butt, and Benn's elation switched to despair. He banged his head in frustration against a ring post before it was finally decided that Galvano had retired from the fight after three torrid rounds.
Immediately after his victory had been confirmed, Benn made straight for his arch-rival, Chris Eubank, who was at the ringside, and said: 'Now we can do some business.' Eubank, the World Boxing Association champion who took Benn's title away nearly two years ago ago, answered: 'OK Nigel, if you want the fight with me, I agree.'
Benn's trainer, Jimmy Tibbs, said: 'The injury was caused by a right over the top of his left lead. There was no head crash. Nigel has won this title fair and square.'
The volatile Italian crowd did not take kindly to the outcome and Benn had to retreat to the dressing room under a hail of paper cups, booing, and whistling. But there was no doubting that Benn deserved his success against the 28-year-old Roman, who is renowned as a master of ring survival.
Galvano was expected to run all night but in the end was more accessible than most experts predicted, with Benn cleverly cutting off his retreat and landing heavy rights. Hemade straight for Galvano from the first bell, banging in hooks to the body and forcing Galvano totally on the defensive. The Italian was happy to hold on and then hit illegally on the break.
Galvano, with just one previous professional defeat, snaked out his left jab in a vain attempt to keep off Benn. But the Briton had the title in his sights when blood appeared on Galvano's eyebrow early in the second.
Benn threw in explosive right-handers, but the exchanges became a little untidy at times because of Galvano's tendency to hold, for which he was warned by New Jersey referee Joe Cortez, who was officiating in his 51st world title contest.
Galvano briefly brought the crowd to its feet by bundling Benn unceremoniously through the ropes in the third, but he hauled himself back claiming no knock-down and Cortez agreed.
The three judges had Benn in the ascendancy, with Frenchman Armand Krief and Belgian Danial Van Der Wiele having him two rounds ahead with one even, while the American, Truck Giampa, had it 2-1 in Benn's favour.