Both clubs' benches clashed during the game, which saw Brighton have two goals controversially denied by VAR decisions.
Then-Spurs boss Cristian Stellini and Brighton manager Roberto de Zerbi were sent off amid the angry scenes. The pair were seen arguing before the game and De Zerbi continued attempted confrontations during the match.
The Football Association fined both clubs £100,000 for failing to conduct themselves in an orderly fashion.
Spurs appealed the fine, and the independent Appeal Board reduced it to £40,000 following a hearing.
A report in part states: “…the behaviour of Brighton and Hove Albion FC was more disorderly than that of Tottenham Hotspur FC in that [Brighton manager] Mr De Zerbi did leave his technical area on the side of the Tottenham technical area and did appear to encroach on Mr Stellini and engage in seemingly provocative behaviour.
"If Mr De Zerbi had not left his technical area on that side then the mass confrontation may not have arisen.”
