It came shining out of the gum shield of his opponent Emilio Correa Bayeaux. Suddenly there was a sharp pain in his chest.
The Cuban sank his teeth into DeGale’s body and while it was not a Mike Tyson-size bite, it hurt the British fighter enough to wince and complain to the referee.
Bayeaux was given two penalty points — and in the end that proved to be the margin of victory for the north Londoner nicknamed “Chunky”.
His opponent had bitten off more than he could chew and DeGale scored a 16-14 victory to win the gold.
Later, the newly-crowned Olympic champion explained: “I was boxing nice in the first round and had scored five points when he got me in a little hold. Then he bit me on the chest, man.
“I could see these little gold teeth coming out of his gum shield.
“He knew he bit me.”
There was a sharp exchange in the post-fight press conference when Bayeaux demanded that DeGale showed him the mark where he had been bitten.
The British fighter rolled down his vest and sure enough there were two teeth marks imprinted on his chest.
The Cuban’s explanation was unconvincing.
“I went towards him with my mouth open and it banged against his chest,” he said.
British boxing coach Terry Edwards laughed it off: “Maybe it was a little love bite.”
There was no love lost in the ring between the two fighters during a contest which at times was a cross between Strictly Ballroom, WWF and a street brawl.
Several times both men went sprawling to the canvas as they wrestled each other around.
DeGale incurred his own penalty points for holding. But when the blows that matter landed they were usually delivered by the Englishman — not that he was appreciated by the Chinese section of the fans, who booed and jeered him when he was awarded the fight.
DeGale said: “That was disrespect, man.
“Those people don’t know what they are talking about. There was a lot of holding and we did end up on the floor a few times. I don’t think it was the best but it was good for me. I got the gold medal and that’s all that matters.”
Meanwhile, Bayeaux was complaining to the bitter end: “The public was not happy and the Chinese people are boxing fanatics. They know what went on.
“They took a point off him for holding and they should have kept taking points off him for the same thing.
“I am not happy with the way the judges scored the fight.”
Those complaints went over the head of DeGale as he deliriously celebrated his golden moment.
But now he has a big decision to make: Does he swap the chance to defend his title in London in 2012 for a £1million contract to turn professional?
It all depends on whether the Amateur Boxing Association and some suitable sponsors deliver some “sensible” money to allow him to box as an amateur for another four years.
DeGale said: “The only way to top this is to win the gold medal again in four years’ time in my home city.
“But for the last four or five months I have been on £1,500 a month and I have to run my car and pay my bills which doesn’t leave me anything. They have to come up with something sensible.
“I need to sign something. For the next four years no one is going to be as good as me. I could turn pro and get £1m but deep in my heart I want to defend in 2012.”