When schoolboy Charlie Line ran onto the pitch during New Zealand's lap of honour, he was not expecting much more than a telling-off.
But the boarding-school pupil was left speechless when he ended up with an All Black star's Rugby World Cup medal hanging around his neck.
Charlie raced onto the pitch to celebrate with his Kiwi heroes as they waved to fans, celebrating their win against Australia on Saturday.
But just as he reached centre player Sonny Bill Williams, he was knocked to the ground by a member of security.
Williams, 30, a former heavyweight boxing champion, picked the teenager up, gave him a hug and put his medal around the teenager's neck.
Charlie, a year 9 pupil at the prestigious independent Millfield School in Somerset, was watching the match with his family, including his brother Will Line and cousin Harry Glenn, who posed for pictures wearing the medal.
Explaining why he gave away his award, Williams said: "He got smoked by the security guard, like full-on tackled. It was pretty sad.
"He's just a young fella obviously caught up in the moment. 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. The way he got round the security guard he could be a future All Black in the making.
"The coaches started joking with me afterwards that it was solid gold.
"I know he'll appreciate it, and when he gets older he'll be telling his kids - that's more special than it just hanging on a wall."
Williams later posted a picture of Charlie on his Instagram account, with the caption: "Only takes one thing to change someone's life. Enjoy it, Charlie bro."
He also said: "The bonds that we have as brothers in the changing room - the medal represents that. But it is more about going back in there and seeing the smiles on the boys' faces and knowing that we have accomplished something that no other All Black team has ever done is pretty special."
Charlie and Will's parents are both British, and were educated at Rugby School, but the two boys are understood to have been born in Singapore, and to have lived in various locations around the world. Their mother, Amanda, is a partner at PWC, the accountants, based in Dubai.
The biggest Rugby World Cup ever broke records on and off the pitch, with tickets sales of more than 2.47?million.
John Key, New Zealand's prime minister, celebrated his country's victory by having dinner with David Cameron, and paid tribute to the All Blacks as "absolute legends".
Bernard Lapasset, the World Rugby chairman, praised "the excitement around the host nation and in Cardiff".