Southampton were in 17th place, tied on 8 points with Newcastle United but also ahead on goal difference.
Ryan Bertrand of Southampton was dismissed for a studs-up challenge in the build-up to the goal, confirmed by the video assistant referee (VAR), two minutes later.
Pérez added the fourth on the 39th minute, with Jamie Vardy scoring on the stroke of half-time to send Leicester into the break ahead 5–0.
As the match took place two days before the first anniversary of the 2018 Leicester helicopter crash, several players dedicated the win to their late owner, Vichai Srivaddhanaprabha, who died in that incident.
[6] Southampton players and coaching staff later donated their wages from the day of the game to a charity run by the club, Saints Foundation.