The Football Association (FA) has fined West Brom and Watford £45,000 apiece after the Premier League duo admitted to a misconduct charge.
West Brom defeated Watford 3-1 at The Hawthorns on December 3, but the match was overshadowed by a clash between the two sides following Roberto Pereyra's red card with six minutes remaining.
Watford's Pereyra had reacted angrily when James McClean kicked the ball towards him while he was on the floor after a challenge.
In a statement on Thursday, the FA said: "The two clubs failed to ensure their players and/or officials conducted themselves in an orderly fashion and/or refrained from provocative behaviour in the 84th minute of their game on 3 December 2016."
High-flying West Brom host Manchester United on Saturday, while Watford are away to cellar-dwelling Sunderland on the same day.