Richarlison appeared to throw a lit flare back into the crowd after scoring for Everton against Chelsea on Sunday.
After a relatively uneventful first half at Goodison Park, the Brazilian striker pounced on a Cesar Azpilicueta mistake to slide the ball past Edouard Mendy to put the hosts in front.
His goal sparked jubilant scenes as Richarlison and his team-mates celebrated at the Gwladys Street End. Amid the celebrations, a flare came onto the pitch, with Richarlison then going to pick it up before hurling it back towards the fans.
His actions have been widely criticised on social media.