Half-time: Leicester 1 Chelsea 0 – Blues behind and Hazard off injured
Eden Hazard went off injured during the first half at the King Power Stadium, where Jamie Vardy put Leicester ahead.
Blues playmaker Hazard was replaced by Pedro on 28 minutes with what looked like a hip problem following a challenge from Vardy, who scored five minutes later.
Riyad Mahrez, who had two early efforts gathered by keeper Thibaut Courtois, delivered a superb cross from the right and striker Vardy volleyed home his 15th goal of the season.
The Foxes were forced into a change of their own when Danny Drinkwater picked up a hamstring injury after a quarter of an hour.
But they remained on the front foot and Vardy’s goal put them within sight of a win that would take them back to the top of the Premier League.
Chelsea: Courtois; Ivanovic, Zouma, Terry, Azpilicueta; Ramires, Matic; Willian, Oscar, Hazard (Pedro 31); Costa.
Subs: Begovic, Cahill, Mikel, Fabregas, Kenedy, Remy.
Subs: Begovic, Cahill, Mikel, Fabregas, Kenedy, Remy.