Cardiff City and Norwich City have been fined by the Football Association after the bad-tempered 1-0 home win for the Bluebirds on 30 July.
Referee Tim Robinson had to deal with a centre-circle scuffle between players, in a match that saw Cardiff's Perry Ng and Canaries' Grant Hanley sent off.
The FA fined Cardiff £17,500 and Norwich £5,000 for breaching rule 20.1.
Both clubs admitted they "failed to ensure players conducted themselves in an orderly fashion".
The FA statement continued: "Norwich FC admitted a charge from the FA and accepted the standard penalty.
"Cardiff City FC admitted a non-standard charge and requested a paper hearing where its fine was imposed by an independent regulatory commission.