His convincing Vardy impression clearly impressed Vardy and his teammates.
Leicester players were banging on the windows of the coach and called out to him as the bus drove past.
Then Ranieri called the bus to a halt and hauled Chapman onto the Vardy party bus.
"All of a sudden, the coach pulls up behind me and all the players and staff are banging on the windows, the door opens and Ranieri is dragging me on," he told the BBC.
"Ranieri and the other players pushed me to the back where Jamie Vardy was and were all shouting and cheering. They obviously knew who I was. It was crazy."
He told Sky News in the United Kingdom he lost his cool upon seeing his heroes in celebration mode and "blurred some of it out".
Then it all went wrong.
As Chapman made his way towards his look-alike, heart beating a thousand times a minute, Vardy couldn't help but crack a joke for his teammates - and Chapman was the target.
Before getting a chance to take a picture with Leicester's top goal-scorer this season, Vardy quipped: "You're an absolute full-kit wanker".
Fortunately, being ripped by his idol in front of his football heroes, appears to be one of the moments Chapman blurred out.
He also got the loudest cheer of the day when Vardy organised for him to be the first player to step off the bus and meet the crowd of fans waiting to receive them at the stadium.
The fans, too, were convinced Chapman was Vardy.
That's exactly what the look-alike wants.
Chapman is now using his 15 minutes of fame to try and secure a role in the production of a film based around Vardy's life story.
Perhaps a stunt double?
Exactly like Vardy, Chapman says he is 29 years old, weighs 76kg and is 1.78m tall.
"I would love that role, purely because the movie needs a pinch of Leicester and I'm Leicester born and Leicester bred," he told Sky News.
"I'm a season ticket-holder and what's better than having a Leicester fan actually play Vardy?"
When asked by a reporter if he can act, Chapman responded: "I'll try".
Until then the Vardy party rolls on.
It began at Vardy's home when Leicester teammates gathered to watch Tottenham's 2-2 draw with Chelsea at Stamford Bridge - the result that secured Leicester the title.
Even though the Foxes still have two matches remaining this season, the celebrations continue.