Leicester move second with a win
Chilwell taps home opener, before VAR sees Bertrand sent off for Saints
Ayoze Perez and Vardy with hat-tricks, Tielemens and Maddison also on target
Southampton into relegation zone
Foxes equal record Premier League win
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Southampton 0-7 Leicester
Substitute Demarai Gray sends a whipped cross into the danger zone, it's hit with pace but so much so that it evades the waiting blue shirts.
The danger comes again down the right as Ricardo Pereira produces another cross which Southampton aren't quite sure how to deal with.
It's left, and falls to Ben Chilwell on the edge of the area but the defender's shot is always rising and fails to test Angus Gunn.
Southampton 0-7 Leicester
Tony Pulis
Former Stoke and West Brom manager on BBC Radio 5 Live
I'd like to see Southampton score to get something out of the game!
Image source, Getty Images#bbcfootball or text 81111
Kyle: Despite Liverpool being so good and a superb side amazing to think this Leicester side now have a better goal difference than them. Leicester have been ruthless tonight just like when they beat 10 man Newcastle a few weeks back they are a joy to watch.
Southampton 0-7 Leicester
For those wondering, Leicester's biggest ever league win was a 10-0 thrashing of Portsmouth in October 1928.
15 minutes to go in this one...
Southampton 0-7 Leicester
Tony Pulis
Former Stoke and West Brom manager on BBC Radio 5 Live
As a manager stood on the line, Hasenhuttl will be devastated and you do take it personally. I've had a few heavy defeats in my time and it's soul destroying.
To sit there and not be able to do anything, you're relying on your players to give everything they've got. It's a very, very lonely place.
Southampton 0-7 Leicester
Ayoze Perez should have his fourth!
Leicester have a corner, and it travels all the way to the back post where Perez is waiting to pounce - but he somehow sends it all the way back across the face of the goal and none of his team-mates can provide the killer touch on this occasion.
That's his last involvement, as he's replaced by Demarai Gray.
Southampton 0-7 Leicester
A first change of the game for Leicester, as Marc Albrighton replaces Harvey Barnes.
Another really promising performance from the 21-year-old winger this evening.
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Just Strauss: Leicester City..... Are They About To Win The League Again ? Liverpool Watch Your Back!
LMW: 7-0. That's the game. As a Saints fan, I'm glad we do bad properly. None of this nondescript 3-0 defeats.
Southampton 0-7 Leicester
This has been a good spell for Southampton.
Nathan Redmond, who has been trying his best to drive his side forward all match, races onto a long ball, gets it under control and whips a shot that forces Kasper Schmeichel into action.
It's just too close to the Leicester goalkeeper to cause Schmeichel any real concerns.
Southampton 0-7 Leicester
James Ward Prowse stands over it...
Not today. Ward-Prowse aims for the bottom right corner but Kasper Schmeichel is on his toes and make slight work of stopping that one.
Southampton 0-7 Leicester
Southampton manage to wrestle possession back as Leicester played around with the ball at the back.
They've won a free-kick around 30-yards out, and it's a rare chance for the hosts to get the ball into the Leicester box...
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Four traffic-strewn hours to bring my Saints fan son to his first game for a first half like that. Football is cruel. So cruel.
Mike S, Watchet.
Image source, Getty ImagesSouthampton 0-7 Leicester
Tony Pulis
Former Stoke and West Brom manager on BBC Radio 5 Live
It's not nice to say but the best thing about this half is the way Leicester have come out. They've been sharp, passage of play incisive. Absolutely first class.
Southampton 0-7 Leicester
Ralph Hasenhuttl looks on from the dugout.
Southampton's biggest ever defeat was an 8-0 loss to Spurs in March 1936 and Everton in November 1971.
In the Premier League, they have lost 7-1 v Everton in November 1996 and Liverpool in January 1999.
This is almost surely going to refresh those records.
Jamie Vardy
This is incredible.
Ben Chilwell has been delivering brilliant crosses from the left all evening and he gets his second assist of the night as he perfectly picks out Jamie Vardy in centre of the box.
It's a great header. And now Vardy will look to match Ayoze Perez' hat-trick...
Image source, Getty ImagesAyoze Perez (Hat-trick)
Ayoze Perez has his hat-trick inside an hour!
Harvey Barnes provides the through-ball, and the Spaniard was never going to miss from there.
Southampton 0-5 Leicester
Lovely, intricate play between Youri Tielemans and Ayoze Perez culminates in Perez unleashing a low shot towards the bottom corner, but Angus Gunn scoops it up relatively untroubled.
Southampton 0-5 Leicester
Tony Pulis
Former Stoke and West Brom manager on BBC Radio 5 Live
It's a lonely job for Hasenhuttl down there now. All he'll be looking for is the players to give everything they've got and try and keep this half a 0-0 at least, that's all he can hope for.
Southampton 0-5 Leicester
It's wave after wave of Leicester City attack at the start of the second half.
The Foxes charge forward with purpose once more, with Harvey Barnes receiving the ball in the box and drawing a good save from Angus Gunn.
There's still desire in the Southampton defence despite the scoreline, but it feels like a matter of time before Leicester extend their already healthy advantage.
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Season ticket holder on honeymoon who never misses a game. What a game to miss. Hassenhuttl out comments are way off the mark, he has been hamstrung with a poor squad due to terrible board decisions. Problems lie at the top.
Charlie, Yeravan, Armenia.