Williams acted after seeing a security guard rugby tackle the boy, who had run on the pitch during the All Blacks’ lap of honour following their 34-17 World Cup final victory over Australia.
Williams, who was photographed intervening then handing the dumbfounded youngster his medal, told New Zealand’s One News afterwards: “I was walking around doing a lap of honour with the boys and a young fella came running out and he got smoked by the security guard, like full-on tackled him. I felt sorry for the little fella.
“If that was a younger brother or cousin I would have given the security guard a hiding. But I just picked the kid up and took him back to his old lady and tried to make the night more memorable for him. Better [for the medal] to be hanging around his neck than mine.”
Williams, who made an instant impact in the final when he came off the bench at the start of the second-half, added that defending the World Cup was “by far the best feeling” he had experienced in his career.
“You’re doing it all with your best mates,” he said. “There’s world class quality players throughout our squad. Everyone dug deep and it’s a very happy way to finish the tournament. I just want to go and enjoy the win — back to back World Cups — with my brothers.”