Middlesbrough have been fined £10,000 after their players “failed to conduct themselves in an orderly fashion” following their defeat by Swansea City.
The club denied the Football Association charge, but an independent regulatory commission upheld it.
The incident on 6 March occurred after Andre Ayew scored a 97th-minute match-winning penalty after referee Gavin Ward initially awarded a corner.
Boss Neil Warnock was also fined £7,000 last week for post-match comments.
Boro, who are ninth in the Championship, were also warned about their future conduct.