•Buoyed by their Champions League win over Borussia Dortmund, Chelsea started brightly and Ben Chilwell volleyed in from a tight angle against his old club.
•Chelsea's Joao Felix and Leicester's Kiernan Dewsbury-Hall hit the woodwork in the space of two minutes, then Felix had a goal ruled out by the video assistant referee for offside.
Chelsea's mini-revival continued with a third victory in a row as they consigned struggling Leicester City to a fifth consecutive defeat.
Buoyed by their Champions League win over Borussia Dortmund, Chelsea started brightly and Ben Chilwell volleyed in from a tight angle against his old club.
Chelsea's Joao Felix and Leicester's Kiernan Dewsbury-Hall hit the woodwork in the space of two minutes, then Felix had a goal ruled out by the video assistant referee for offside.
Patson Daka rifled home an excellent equaliser after Ricardo Pereira won the ball off the dawdling Felix outside the box.
But Kai Havertz pounced six minutes into first-half injury time with an excellent dinked finish from Enzo Fernandez's clever aerial ball.
Mykhailo Mudryk thought he had his first goal for the Blues after the break but his effort was disallowed for offside.
Mateo Kovacic sealed the win as he volleyed in from Mudryk's header.
The sliding Foxes, who ended with 10 men following Wout Faes' late dismissal for a second booking, now just sit one point outside the relegation zone.
Chelsea have now despatched Leeds, Dortmund and Leicester in the space of eight days - having failed to win in the previous six games spread over five weeks.
This ended their worst run without an away win since 2000-01, having failed to win in their last 10 games on the road since October.
Graham Potter will be hoping this is the turning point after a difficult start in his first role at one of Europe's biggest teams. They are still only 10th but now sit just two points off a potential European place.
They led from their first major chance when Chilwell met Kalidou Koulibaly's cross to smash home, a goal he celebrated against his former employers.
It could have been even better with Felix clipping a shot past Danny Ward which hit the post, then finding the net from Ruben Loftus-Cheek's cross. With everyone back at the centre circle ready to restart, it was ruled out by the VAR because Felix was offside.
Havertz did put them back into the lead with a clever finish from Fernandez's ball.
The £89m Ukraine forward Mudryk sped away from Leicester's defence to slot in but he was ruled outside. Not long after he had his first assist in English football as Havertz crossed from the right and Mudryk headed down for Kovacic to lash in.
The goal was checked by the VAR for a potential Havertz offside but the goal was given.