Argentine fans mistakenly stoned their team Club Atletico Tigre's bus while they were en route to play Brazil's Sao Paulo in a Copa Sudamericana group match on Thursday.
With a history of bad blood between the teams following the controversial final of the 2012 tournament, there was heavy police presence for the showdown, which Sao Paulo won 2-0.
Tigre midfielder Agustin Cardozo flagged up the incident on Instagram, uploading a photo of a stone in his hands with a broken window in the background and the caption "it's us."
Although he later deleted the post, Argentine media outlet TyC captured video footage of the damage to the vehicle.
In the 2012 final, Sao Paulo were leading 2-0 and were awarded the win after the referee called off the match in the second half due to Tigre players refusing to come out onto the pitch.