Crystal Palace fans reportedly vandalised a team coach thinking that it belonged to Middlesbrough when it was in fact the Eagles' own.
The incident occurred prior to Saturday's 1-0 victory over Boro at Selhurst Park.
The coach, which was parked outside a hotel near the ground, had 'Crystal Palace FC' graffitied along the side of it onto a blue and red background.
According to the Daily Mail, Palace's assistant head groundsman Dean Waters confirmed on Twitter that fans had made the blunder.
He is believed to have tweeted: "£40,000 worth of damage on our coach thinking it was the Boro coach. Nice one! #cpfc."