The post-match melee between Manchester City and Arsenal players and staff was sparked by a snubbed handshake.
After Arsenal's 1-0 win, their set-piece coach Nicolas Jover offered his hand to City fullback Kyle Walker, who promptly ignored him.
This led to Jover saying something to Walker, who double-backed to confront the coach, who had previously worked at City.
A minor scuffle ensued as members of both teams intervened but cooler heads eventually prevailed.
Both Walker and Erling Haaland had to be held back by teammates before they were ushered down the players' tunnel.