Sheffield United and Southampton have been fined £20,000 each by the Football Association following their flare-up at Bramall Lane.
The clubs were charged for a breach of FA rule E20 after tempers boiled over late on in Saints' 2-0 win on March 6.
The incident came in the first of three minutes added on when United midfielder John Fleck fouled Southampton forward Che Adams.
Fleck was shown a yellow card for the challenge, checked by VAR, but Saints' players surrounded referee Paul Tierney demanding more, with Blades striker Oli McBurnie and Southampton defender Jannik Vestergaard booked for their reactions.
The FA said: "Both clubs admitted failing to ensure that their players conducted themselves in an orderly fashion during the 90th minute and accepted the standard penalty."