Leicester City returned to the top of the Premier League and increased the pressure on Chelsea manager Jose Mourinho with victory at King Power Stadium.
Jamie Vardy's 15th goal of the season put Leicester ahead before half-time and Riyad Mahrez's brilliant curling strike just after the break sealed the win for Claudio Ranieri's side.
Chelsea substitute Loic Remy pulled one back but Leicester survived in relative comfort to move back ahead of Manchester City at the top of the table.
The reigning Premier League champions, in contrast, lie just a point off the relegation zone in 16th place with Mourinho fighting for survival.
Follow all the reaction to Leicester's win over Chelsea
Riyad Mahrez turned Cesar Azpilicueta inside out before putting the hosts 2-0 up
The 'Tinkerman' torments the 'Special One'
Ranieri has been in Mourinho's shadow from the time he was succeeded at Stamford Bridge by "The Special One" in 2004 and relations between the pair have often been fractious.
They are more cordial now - but how the 64-year-old, hugely popular Italian will have enjoyed the sweet taste of victory against his former club on Monday.
Fans dream, players calm - Ranieri
Chelsea have looked lethargic on many occasions this season but rarely have they looked as ragged, pedestrian and off the pace as they were against the Foxes.
From the first whistle the pace and movement of Jamie Vardy and Riyad Mahrez immediately exposed John Terry, in particular, in the style that has troubled so many teams on Leicester's remarkable rise to the top.
As Leicester pressed and pushed, Chelsea retreated on to the back foot. Ranieri's side looked high on confidence and adrenalin, the reigning champions fearful and tentative.
It was barely believable that only seven months ago Chelsea were crowned champions and Leicester were pulling off a remarkable escape from what looked certain relegation. This night underscored what has been a remarkable role reversal this season, and ensured Leicester's best start to a top-flight season in their 131-year history.
- Savage v Terry: Round three
How much longer can Mourinho survive?
Jose Mourinho said afterwards that his team's chances of reaching the top four had gone
The Premier League title and credit in the bank means Mourinho has been afforded far more patience than is customary by owner Roman Abramovich.
Leicester deservedly inflicted a ninth loss in 16 games on Chelsea at a thunderous King Power Stadium and with suggestions Mourinho could ill-afford to lose either here or against Porto in the Champions League, he has surely been pushed closer to the edge.
Chelsea have 'no chance' of top four
Mourinho has said Abramovich would not "change with the wind" - but it is firmly blowing against the Portuguese now and he will need something out of character with Chelsea's season to survive.
He may be getting a stay of execution because there is no natural heir apparent or guarantee of improvement - the currently unemployed Carlo Ancelotti having already experienced a sacking at Abramovich's hands.
It is highly unlikely, and against all his natural instincts, that Abramovich will let this continue. And with the prospect of any European football of any kind next season receding, the clock must be ticking.
- 'Go and get me a cup of tea, Cesar Azpilicueta'
Time up for John Terry?
Chelsea had two shots in the first half, but after withdrawing John Terry and going to a 3-4-3 formation they managed nine in the second as they adopted a more attacking approach
John Terry has been the bedrock of all Chelsea's modern-day successes - but the centre-back looked old and fraying at the edges in the face of the pace, verve and movement of Vardy and Mahrez.
He was not alone as they threatened to run Chelsea's defence ragged and Terry being replaced by Cesc Fabregas after only 53 minutes was a sign of the times, not just of this night.
Terry has been a magnificent servant for Chelsea but the captain who turned 35 on 7 December looks like he is feeling Father Time's tap on his shoulder.
Throw in 31-year-old Branislav Ivanovic, a shadow of his former self this season, and you are left with a Chelsea defence in need of serious renewal despite the promise of Kurt Zouma, 21.
Mourinho recognised as much in the summer when Chelsea edged the bidding up towards £40m for Everton's John Stones, only to be met with total resistance at Goodison Park.
They could, of course, return for Stones in January but Everton's mood has not changed. The young defender is now firmly settled and is unlikely to want any potential upheaval anyway with Euro 2016 on the horizon.
The sight of Terry making his way to the bench so early on in the second half only emphasises the urgency of Chelsea's defensive plight.
Man of the match: Riyad Mahrez
Riyad Mahrez has been involved in a league-high 18 goals this season (11 goals, seven assists)
Stats you need to know
- Leicester have scored in every Premier League game this season.
- Jamie Vardy has now scored or assisted in 14 consecutive Premier League games.
- Only Borussia Dortmund's Pierre-Emerick Aubameyang (18) has netted more goals in Europe's top five leagues this season than Jamie Vardy (15).
- That was Chelsea and Jose Mourinho's ninth defeat in the Premier League this season - the same number as in 2013-14 (6) and 2014-15 (3) combined.
- The Blues have lost 9+ of their opening 16 top-flight games for the first time since 1978-79, a season in which they were relegated.
- Ninety-six teams have gained 15 points or fewer from their opening 16 games, 50 were relegated and the average finishing position of those 96 teams was 17th.
What next?
Leicester will have a further test of their title credentials in their next three games, away at Everton on Saturday, then a trip to Liverpool on Boxing Day before hosting Manchester City on 29 December. Chelsea host Sunderland and Watford before travelling to Manchester United on 28 December.
Lineup, Bookings (2) & Substitutions (6)
Leicester City
- 01 Schmeichel
- 17 Simpson
- 05 Morgan
- 06 Huth Booked
- 28 Fuchs
- 26 Mahrez (Inler - 82' )
- 04 Drinkwater (King - 17' )
- 14 Kanté
- 11 Albrighton
- 23 Ulloa
- 09 Vardy Booked (Okazaki - 88' )
Substitutes
- 10 King
- 20 Okazaki
- 24 Dyer
- 27 Wasilewski
- 29 Benalouane
- 32 Schwarzer
- 33 Inler
Chelsea
- 13 Courtois
- 02 Ivanovic
- 05 Zouma
- 26 Terry (Fàbregas - 53' )
- 28 Azpilicueta
- 07 Ramires
- 21 Matic
- 22 Willian
- 08 Oscar (Remy - 65' )
- 10 Hazard (Pedro - 31' )
- 19 Diego Costa
Substitutes
- 01 Begovic
- 04 Fàbregas
- 12 Mikel
- 16 Kenedy
- 17 Pedro
- 18 Remy
- 24 Cahill
Match Stats
Live Text Commentary
Full Time Match ends, Leicester City 2, Chelsea 1.
90:00 +5:19 Full timeFull Time Second Half ends, Leicester City 2, Chelsea 1.
90:00 +3:47Pedro (Chelsea) wins a free kick in the defensive half.
90:00 +3:47Foul by Leonardo Ulloa (Leicester City).
90:00 +3:06Foul by Nemanja Matic (Chelsea).
90:00 +3:06Leonardo Ulloa (Leicester City) wins a free kick on the right wing.
90:00 +1:48Attempt missed. Leonardo Ulloa (Leicester City) left footed shot from the right side of the box is high and wide to the left. Assisted by Shinji Okazaki.
87:23 SubstitutionSubstitution Substitution, Leicester City. Shinji Okazaki replaces Jamie Vardy.
86:42César Azpilicueta (Chelsea) wins a free kick in the defensive half.
86:42Foul by Leonardo Ulloa (Leicester City).
84:22Hand ball by Leonardo Ulloa (Leicester City).
83:47Attempt missed. Loïc Remy (Chelsea) right footed shot from outside the box misses to the left. Assisted by Willian.
83:19Willian (Chelsea) wins a free kick in the attacking half.
83:19Foul by Leonardo Ulloa (Leicester City).
82:55Attempt missed. Marc Albrighton (Leicester City) right footed shot from outside the box is close, but misses to the left. Assisted by N'Golo Kanté.
81:11 SubstitutionSubstitution Substitution, Leicester City. Gökhan Inler replaces Riyad Mahrez.
80:31Attempt blocked. Pedro (Chelsea) header from the centre of the box is blocked.
79:58Loïc Remy (Chelsea) wins a free kick on the right wing.
79:58Foul by N'Golo Kanté (Leicester City).
78:14Foul by César Azpilicueta (Chelsea).
Riyad Mahrez (Leicester City) wins a free kick in the defensive half.
76:45 Goal scoredGoal! Goal! Leicester City 2, Chelsea 1. Loïc Remy (Chelsea) header from very close range to the centre of the goal. Assisted by Pedro with a cross.
72:54Foul by César Azpilicueta (Chelsea).
72:54Jamie Vardy (Leicester City) wins a free kick in the defensive half.
70:46Hand ball by N'Golo Kanté (Leicester City).
69:05Corner, Chelsea. Conceded by Christian Fuchs.
66:47Attempt blocked. Nemanja Matic (Chelsea) left footed shot from outside the box is blocked. Assisted by Willian.
66:29Attempt blocked. Robert Huth (Leicester City) header from the centre of the box is blocked. Assisted by Marc Albrighton with a cross.
66:02Corner, Leicester City. Conceded by Branislav Ivanovic.
65:30Attempt saved. Cesc Fàbregas (Chelsea) header from the centre of the box is saved in the centre of the goal. Assisted by Pedro with a cross.
64:55 SubstitutionSubstitution Substitution, Chelsea. Loïc Remy replaces Oscar.
64:37Ramires (Chelsea) wins a free kick in the attacking half.
64:37Foul by Jamie Vardy (Leicester City).
61:57Attempt blocked. Branislav Ivanovic (Chelsea) right footed shot from the right side of the six yard box is blocked.
61:56Attempt blocked. Branislav Ivanovic (Chelsea) right footed shot from the right side of the six yard box is blocked.
61:34Corner, Chelsea. Conceded by Kasper Schmeichel.
61:31Attempt saved. Diego Costa (Chelsea) right footed shot from the centre of the box is saved in the bottom right corner. Assisted by Cesc Fàbregas with a through ball.
61:09Willian (Chelsea) wins a free kick in the attacking half.
61:09Foul by N'Golo Kanté (Leicester City).
57:40Corner, Chelsea. Conceded by Jamie Vardy.
57:37Attempt blocked. Willian (Chelsea) right footed shot from outside the box is blocked.
57:02Pedro (Chelsea) wins a free kick in the attacking half.
57:02Foul by Robert Huth (Leicester City).
54:20Delay over. They are ready to continue.
53:08Delay in match Andy King (Leicester City) because of an injury.
52:51 SubstitutionSubstitution Substitution, Chelsea. Cesc Fàbregas replaces John Terry.
49:58 BookingBooking Robert Huth (Leicester City) is shown the yellow card for a bad foul.
49:54Diego Costa (Chelsea) wins a free kick on the right wing.
49:54Foul by Robert Huth (Leicester City).
47:23 Goal scoredGoal! Goal! Leicester City 2, Chelsea 0. Riyad Mahrez (Leicester City) left footed shot from the right side of the box to the top left corner. Assisted by Marc Albrighton.
45:28 BookingBooking Jamie Vardy (Leicester City) is shown the yellow card for a bad foul.
45:21Diego Costa (Chelsea) wins a free kick in the defensive half.
45:21Foul by Jamie Vardy (Leicester City).
45:00Second Half begins Leicester City 1, Chelsea 0.
45:00 +3:03 Half timeHalf Time First Half ends, Leicester City 1, Chelsea 0.
45:00 +1:23Diego Costa (Chelsea) wins a free kick in the defensive half.
45:00 +1:23Foul by Robert Huth (Leicester City).
45:00 +0:12Willian (Chelsea) wins a free kick in the defensive half.
45:00 +0:12Foul by Marc Albrighton (Leicester City).
44:38Foul by César Azpilicueta (Chelsea).
44:38Riyad Mahrez (Leicester City) wins a free kick in the attacking half.
43:46Attempt saved. Marc Albrighton (Leicester City) right footed shot from outside the box is saved in the bottom left corner. Assisted by N'Golo Kanté.
40:54Diego Costa (Chelsea) wins a free kick in the defensive half.
40:54Foul by Danny Simpson (Leicester City).
39:45Offside, Chelsea. Willian tries a through ball, but Diego Costa is caught offside.
38:42Corner, Chelsea. Conceded by Danny Simpson.
36:09Foul by Kurt Zouma (Chelsea).
36:09Jamie Vardy (Leicester City) wins a free kick on the left wing.
35:23Nemanja Matic (Chelsea) hits the bar with a header from the centre of the box. Assisted by Willian with a cross following a corner.
34:55Corner, Chelsea. Conceded by Marc Albrighton.
33:03 Goal scoredGoal! Goal! Leicester City 1, Chelsea 0. Jamie Vardy (Leicester City) right footed shot from the centre of the box to the bottom right corner. Assisted by Riyad Mahrez with a cross.
32:14Foul by Oscar (Chelsea).
32:14Marc Albrighton (Leicester City) wins a free kick in the defensive half.
31:16Attempt missed. N'Golo Kanté (Leicester City) right footed shot from outside the box is high and wide to the right. Assisted by Marc Albrighton.
30:10 SubstitutionSubstitution Substitution, Chelsea. Pedro replaces Eden Hazard because of an injury.
29:13Delay over. They are ready to continue.
27:39Delay in match Eden Hazard (Chelsea) because of an injury.
26:47Nemanja Matic (Chelsea) wins a free kick on the left wing.
26:47Foul by Jamie Vardy (Leicester City).
23:15Corner, Chelsea. Conceded by Marc Albrighton.
20:29Offside, Chelsea. Thibaut Courtois tries a through ball, but Diego Costa is caught offside.
18:01Attempt saved. Riyad Mahrez (Leicester City) left footed shot from the left side of the box is saved in the centre of the goal.
16:05 SubstitutionSubstitution Substitution, Leicester City. Andy King replaces Daniel Drinkwater because of an injury.
15:43Delay over. They are ready to continue.
14:54Delay in match Daniel Drinkwater (Leicester City) because of an injury.
14:27Eden Hazard (Chelsea) wins a free kick in the attacking half.
14:27Foul by N'Golo Kanté (Leicester City).
13:56Attempt blocked. Eden Hazard (Chelsea) left footed shot from the left side of the box is blocked. Assisted by Oscar with a cross.
11:32Riyad Mahrez (Leicester City) wins a free kick in the attacking half.
11:32Foul by John Terry (Chelsea).
3:53Marc Albrighton (Leicester City) wins a free kick in the defensive half.
3:53Foul by Ramires (Chelsea).
2:55Corner, Chelsea. Conceded by Robert Huth.
2:26Corner, Chelsea. Conceded by Robert Huth.
1:12Attempt saved. Riyad Mahrez (Leicester City) left footed shot from outside the box is saved in the bottom right corner.
0:00First Half begins.
0:00Lineups are announced and players are warming up.
Live data and text provided by our data suppliers
