The Duke of Cambridge was pictured celebrating at Wembley Stadium when his beloved Aston Villa scored in the League Cup final.
The Birmingham side scored shortly before half-time, giving the team hope that they could come back as Manchester City had been leading 2-0.
The future king jumped out of his seat to celebrate wildly with two friends as striker Mbwana Samatta headed a cross into the net.
But Prince William, who is the president of the Football Association, was later pictured looking more sombre in his cap and coat when the final whistle blew as City won 2-1.
The second in line to the throne is known to be a loyal follower of Villa, and took his son George, six, and the Duchess of Cambridge to a game against Norwich earlier this season.
In 2015, he told Gary Lineker he supported the team because all his school friends were either Manchester United or Chelsea fans and he wanted to be different.
He said: "A long time ago at school I got into football big time.
"I was looking around for clubs. All my friends at school were either Man United fans or Chelsea fans and I didn't want to follow the run of the mill teams.
"I wanted to have a team that was more mid-table that could give me the more emotional rollercoaster moments.
"Aston Villa's always had a great history.
"I have got friends of mine who support Aston Villa and one of the first FA Cup games I went to was Bolton v Aston Villa back in about 2000.
"It was fantastic, I sat with all the fans with my red beanie on, and I was sat with all the Brummie fans and I had a great time.
"It was just the atmosphere, the camaraderie and I really felt that there was something I could connect with."
Aston Villa are currently struggling in the Premier League and are threatened with relegation.
