First-half goals by Wilfred Ndidi and James Maddison powered Leicester City to the top of the Premier League in Brendan Rodgers' first career win against Chelsea.
Ndidi fired the Foxes ahead from the edge of the penalty area on six minutes following a well-worked corner.
Jamie Vardy's scooped effort was then kept out on 34 minutes thanks to a touch from Blues goalkeeper Edouard Mendy.
On 38 minutes, Chelsea were awarded a penalty after Jonny Evans fouled Christian Pulisic, but a VAR review showed the offence had taken place just outside the area.
Mason Mount fired the resulting free-kick over the crossbar and seconds later, a defensive mix-up at the other end allowed Maddison to make it 2-0.
James Justin sent a free header wide and Youri Tielemans had a shot well saved by Mendy on 57 minutes as the dominant hosts threatened a third.
They closed out an assured 2-0 win after Timo Werner's late effort that was disallowed for offside.
With 19 matches played, Leicester are top with 38 points, one ahead of Manchester United, who have played a match fewer and face Fulham on Wednesday.
Chelsea lie eighth on 29 points.
Leicester: 27 Jan v Everton (A)
Chelsea: 27 Jan v Wolves (H)
Referee: Craig Pawson. Assistants: Ian Hussin, Sian Massey-Ellis. Fourth official: Jonathan Moss. VAR: Andre Marriner. Assistant VAR: Stephen Child.