Chris Wood hit a first-half hat-trick as dominant Leicester sent Bristol City to the foot of the Championship.
Wood cut inside and drove home his first goal after 11 minutes, before pouncing on goalkeeper Dean Gerken's error to tap in his second.
Gerken looked culpable again as Wood's 20-yard shot squirmed under his body for the striker's hat-trick.
Matty James rifled into the corner just after the break to compound the woes of Derek McInnes' side.
Former Robins loanee Wood now has nine goals in his last five games, and six in three games since joining the Foxes in a £1m deal from West Brom .
Winger Ben Marshall provided the ammunition for the first goal, playing a precise pass that Wood controlled before firing home.
Leicester then capitalised on poor goalkeeping as Gerken failed to make sufficient contact on a punch, allowing Wood to tap in the loose ball.
Wood scored again just before the break, unleashing a shot that evaded Gerken to complete a quick-fire hat-trick.
Things got worse for the hosts when they sloppily conceded possession inside their own half, and James picked out the bottom-right corner to make it 4-0.
The hosts slowly stirred into life in the final 20 minutes, but Foxes keeper Kasper Schmeichel denied Paul Anderson and Liam Kelly.
The home crowd's warmest applause was reserved for the substitution of New Zealand international Wood in an acknowledgement of his superb display.
Leicester boss Nigel Pearson:
"Chris Wood has taken his chances for us and scored some early goals, which makes a big difference.
"He is a very focused young player who has fitted in straight away and gives us a height and physical presence up front, which perhaps we lacked.
"It is not easy to sign quality players in January and I am delighted to have secured him early in the window.
"We created a lot of chances to today and I am also very pleased to have kept a clean sheet."
Bristol City manager Derek McInnes:
"A lot of players let the fans down in the first half today.
"The first three goals were self-inflicted. Dean Gerken would say himself that he didn't have the best of games, but there were errors in front of him as well.
"We were too pedestrian in our play and made it easy for a very good Leicester team. I am looking to sign a few players before the transfer window closes.
- 22 Gerken
- 02 Foster
- 04 Fontaine
- 12 Wilson (Bryan - 46' )
- 17 Cunningham
- 19 McManus
- 10 Kelly (Reid - 78' )
- 14 Skuse
- 15 Pearson
- 09 Stead (Anderson - 46' )
- 16 Davies
- 01 Heaton
- 26 Bryan
- 21 Anderson
- 24 Reid
- 25 Elliott
- 18 Taylor
- 29 Burns
- 01 Schmeichel
- 02 De Laet
- 03 Konchesky
- 05 Morgan
- 15 M Keane
- 04 Drinkwater
- 07 Marshall (Gallagher - 72' )
- 16 James
- 24 Knockaert (Dyer - 20' )
- 35 Nugent
- 39 Wood (Waghorn - 61' )
- 13 Logan
- 22 Moore
- 10 King
- 11 Dyer
- 17 Gallagher
- 14 Waghorn
- 29 Futacs
Live Text Commentary
Full Time The final whistle is blown by the referee.87:47
Effort from the edge of the penalty area by Greg Cunningham goes wide of the left-hand post.87:09
Paul Gallagher takes a shot. Save by Dean Gerken.86:29
Foul by Richard Foster on Martyn Waghorn, free kick awarded. The free kick is delivered right-footed by Paul Gallagher from left wing, clearance by Stephen McManus.85:36
Shot on goal by Stephen Pearson from just inside the area clears the crossbar.80:42
Greg Cunningham takes a shot from long range which goes wide right of the goal.80:06
Bobby Reid takes a short corner.79:29
Free kick awarded for a foul by Ritchie De Laet on Paul Anderson. Direct free kick taken by Greg Cunningham.77:47
Cole Skuse takes the free kick.77:47 Substitution
Substitution Liam Kelly goes off and Bobby Reid comes on.77:47
Martyn Waghorn concedes a free kick for a foul on Cole Skuse.76:21
Foul by Cole Skuse on Matty James, free kick awarded. Martyn Waghorn has a direct shot on goal from the free kick.76:02
Stephen McManus gives away a free kick for an unfair challenge on Martyn Waghorn. Martyn Waghorn takes the direct free kick.72:39
Liam Kelly takes a shot. Kasper Schmeichel makes a save.71:35 Substitution
Substitution Paul Gallagher joins the action as a substitute, replacing Ben Marshall.69:30
Corner from the right by-line taken by Paul Anderson, Martyn Waghorn manages to make a clearance.69:01
Paul Anderson takes a shot. Save made by Kasper Schmeichel.65:51
Effort on goal by Lloyd Dyer from deep inside the penalty area misses to the right of the goal.64:04
Ben Marshall has an effort at goal from outside the area which goes wide right of the goal.60:30 Substitution
Substitution (Leicester) makes a substitution, with Martyn Waghorn coming on for Chris Wood.
Greg Cunningham has an effort at goal from outside the box which goes wide right of the goal.59:36
Chris Wood concedes a free kick for a foul on Greg Cunningham. Stephen McManus restarts play with the free kick.54:39
Chris Wood fouled by Liam Fontaine, the ref awards a free kick. Direct free kick taken by Danny Drinkwater.48:44
Assist on the goal came from Ben Marshall.48:44 Goal scored
Goal! - Matty James - Bristol C 0 - 4 Leicester Matty James gets on the score sheet with a goal from long range to the bottom right corner of the goal. Bristol City 0-4 Leicester.47:12
Outswinging corner taken left-footed by Steven Davies from the left by-line, Stephen McManus takes a shot. Blocked by Michael Keane.45:58
Effort from the edge of the penalty box by Ben Marshall goes wide of the right-hand upright.45:01
The referee starts the second half.45:01 Substitution
Substitution Joe Bryan is brought on as a substitute for James Wilson.45:01 Substitution
Substitution Paul Anderson replaces Jon Stead.45:00 +0:49 Half time
Half Time It is the end of the first-half.44:20
Stephen Pearson fouled by Ritchie De Laet, the ref awards a free kick. Direct free kick taken by Greg Cunningham.43:14
Corner taken left-footed by Steven Davies from the left by-line, Wes Morgan makes a clearance.40:26
Assist on the goal came from Matty James.40:26 Goal scored
Goal! - Chris Wood - Bristol C 0 - 3 Leicester A goal is scored by Chris Wood from just outside the area low into the middle of the goal. Bristol City 0-3 Leicester.36:49
Lloyd Dyer decides to take a short corner.35:30
Free kick awarded for an unfair challenge on Liam Kelly by Danny Drinkwater. Dean Gerken takes the direct free kick.33:19
Matty James takes a shot. Save by Dean Gerken.30:03
Steven Davies is caught offside. Kasper Schmeichel takes the free kick.29:45
The referee blows for offside. Free kick taken by Stephen McManus.26:14
Ben Marshall takes a shot. Blocked by Liam Fontaine. Corner taken right-footed by Ben Marshall, James Wilson makes a clearance.25:08
Inswinging corner taken right-footed by Steven Davies from the right by-line to the near post, clearance made by Wes Morgan.20:40
Shot on goal by Chris Wood from inside the box goes harmlessly over the target.20:24
Floated corner taken by Ben Marshall from the right by-line.19:51
Ben Marshall takes a outswinging corner to the near post, clearance by Steven Davies.19:08 Substitution
Substitution Lloyd Dyer on for Anthony Knockaert.17:34 Goal scored
Goal! - Chris Wood - Bristol C 0 - 2 Leicester Chris Wood fires in a goal from inside the six-yard box low into the middle of the goal. Bristol City 0-2 Leicester.17:12
Inswinging corner taken by Ben Marshall, save by Dean Gerken.16:21
Anthony Knockaert takes a shot. Save by Dean Gerken.14:18
Unfair challenge on Steven Davies by Wes Morgan results in a free kick. Direct free kick taken by Liam Kelly.10:37
Assist on the goal came from Ben Marshall.10:37 Goal scored
Goal! - Chris Wood - Bristol C 0 - 1 Leicester Chris Wood finds the back of the net with a goal from the edge of the penalty area to the bottom left corner of the goal. Bristol City 0-1 Leicester.7:29
Ben Marshall takes a shot. Liam Fontaine gets a block in.2:28
Shot by Paul Konchesky went harmlessly over the bar.0:00
The referee gets the game started.
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