Leicester City equalled the 24-year-old record for the biggest ever Premier League victory as 10-man Southampton were dismantled at a rainswept St Mary's.
The victory sees Brendan Rodgers' side climb into second place, leapfrogging Manchester City and moving five points behind leaders Liverpool.
The result, which matches Manchester United's 9-0 win against Ipswich in 1995, was only confirmed in stoppage time thanks to Jamie Vardy's penalty.
Leicester manager Brendan Rodgers, speaking to BBC Match of the Day:
"I'm very pleased to see our work rate, we scored some great goals and we were very hungry tonight. It was horrible weather but our focus was outstanding. I'm very pleased with how we defended, and we were ruthless. I'm very proud to stand and be the manager of that team.
"We wanted to get the ball back quickly and attack again. A mark of the good sides is you don't let up. We wanted to show we're a good side and we certainly did that in the second half.
"We were ruthlessly simple in our game. When you're so many goals up you can easily slow but we kept focused. We want to be a top team and to be a top team you must be clinical.
"It was a very good team performance and we're pleased to keep a clean sheet. It's good for our goals for but the clean sheet is equally important."
Southampton manager Ralph Hasenhuttl, speaking to BBC Match of the Day:
"That was one of the tough one's tonight. The performance was a disaster today and I have to apologies and take 100% responsibility - I've never seen a team act like this, there was no fight for anything.
"It was horrible to watch and everyone who stayed to watch is really a fan of this football club. Leicester were in every part of the game better than us I'm a proud man but the way we play today is not the way I want to see my team play. We must get our heads up and that is my job in the next few days.
"I said we must play to the last minute but I can understand why the fans that left. We all must to do everything to pull this back. I haven't looked at the [Ryan Bertrand] red card but it doesn't make any difference in this moment."
On what was said after the game: "There is nothing I want to speak of here in front of the camera - we keep that for in the dressing room."