Jamie Vardy and Ayoze Perez both scored hat-tricks as the Foxes belted the Saints by nine goals
Southampton coach Ralph Hasenhuttl took full responsibility after Saints suffered their largest-ever defeat in a 9-0 hammering by Leicester at St. Mary's on Friday.
The Foxes scored three goals in the first 19 minutes, aided by a straight red card to Ryan Bertrand as Jamie Vardy and Ayoze Perez both completed hat-tricks in the second half.
The result plunges Southampton into the relegation zone on goal difference as they remain without a home win in the league since April.