The prolific Vardy, whose record run of 11 consecutive Premier League goals came to an end at Swansea City last weekend, beat goalkeeper Thibaut Courtois with a crisp volley from playmaker Mahrez's delightful cross after 34 minutes.
Algeria international Mahrez curled in a stunning second from the edge of the area three minutes into the second half to put Leicester, continuing a remarkable turnaround after escaping relegation last season, on 35 points, two clear of Arsenal.
Substitute Loic Remy gave the visitors hope with a close-range headed goal 13 minutes from time to set up a tense finish but the hosts held out to leave Chelsea mired in 16th place on 15 points from 16 games -- one point above the relegation zone.
"We played against the champions but we want to make a fantastic match for our fans because they believe, they are dreaming," said Leicester manager Claudio Ranieri, savouring victory against his former side.
"It is good if they (the fans) continue to dream but for us it was important to make a great performance with a fantastic spirit. Also tactically, I am very satisfied. We concentrated for 95 minutes against the champions. That is not easy."
Chelsea manager Jose Mourinho agreed. "They deserved to win because they were better than us during a longer period of time," he said. "We were the best team for 20-25 minutes, maybe a maximum of 30 minutes. They were the best team for an hour."
Victory was extra sweet for Ranieri who was sacked by Chelsea in 2004, a year after Russian billionaire Roman Abramovich took ownership of the London club.
Ranieri had led Chelsea to their highest league placing for 49 years and their first Champions League semi-final, which they lost to AS Monaco, but his reward was the sack.
He was replaced by Jose Mourinho whose second spell in charge of Chelsea has come increasingly under the spotlight.
They have lost nine of their opening 16 top-flight games for the first time since 1978-79, a season in which they were relegated.
HAZARD INJURED
Chelsea's woes were compounded by a first-half injury suffered by their Belgium forward Eden Hazard who hobbled off with an apparent hip problem after a challenge from Premier League top scorer Vardy.
England striker Vardy (15 goals) and Mahrez (11) have scored 26 times between them this season and they again lit up the King Power stadium with their intelligent running, pace and trickery.
Leicester, with one league defeat since losing at home to Chelsea in April -- a run of 20 games -- had the swagger of side sky-high on confidence and a dominant start was rewarded with Vardy's opener.
With that sense of anticipation of a striker at the top of his game, he escaped the attentions of John Terry to send a fizzing volley past Courtois from the influential Mahrez's seventh assist of the season.
Chelsea rarely threatened in the first half and when Mahrez beat Courtois with a sumptuous strike, Mourinho's men had it all to do.
They huffed and puffed without any spark until Remy headed in fellow substitute Pedro's cross but they failed to create any meaningful chances to salvage a point and take some of the pressure off their beleaguered manager.
(Editing by Ken Ferris)
Share
