Middlesbrough moved four points clear of the relegation zone with a thumping victory against 10-man Bristol City.
Boro forward Leroy Lita, who started his career at City, was the main architect of their downfall.
His shot just before the break was diverted into the City net by Robins defender Kalifa Cisse while Lita headed Boro's second after the restart.
Barry Robson scored the third before Lita converted a late penalty after David James was sent off.
It was a win that took Boro to within two points of City and ensured Tony Mowbray's team bounced back from their FA Cup exit at League Two Burton last weekend.
While it was Boro's biggest win of the season, it was the heaviest defeat for Keith Millen's side and ensured a second successive miserable afternoon at Ashton Gate after last Saturday's Cup exit against Sheffield Wednesday.
City had only lost three of their 14 Championship fixtures and had not been beaten in their last eight home league fixtures but they were very poor on Saturday.
The contest was virtually without incident until the unfortunate Cisse diverted Lita's low cross beyond David James and into his own net shortly before the interval.
Gary O'Neil, one of several Boro players linked with moves away from the club in January, twice forced James into action with long-range strikes, while a shot from the impressive Andrew Tayor deflected wide off Cisse.
It was a difficult afternoon for makeshift central defender Cisse, who was caught out of position several times, had an attempted clearance charged down by Lita and put the ball in his own net when it would have been easier to let James deal with the danger.
The home team were far too direct, allowing David Wheater and Matthew Bates to easily clear much of the danger.
Brett Pitman and Jon Stead worked hard but received precious little good service. Pitman, with eight goals in his previous eight games, was inches away from connecting with a cross from Stead and shot wide shortly before the break from a tight angle.
The quality did not really improve after the interval but once again poor defending from City contributed to their own downfall.
First Cisse missed out on the chance to head clear and then, after Boro had worked the ball out to the right flank, Steven Caulker allowed a cross from substitute Tony McMahon to bounce and Lita headed beyond James from six yards.
Cisse was withdrawn shortly afterwards, while Lita continued to menace his former team, narrowly shooting over with a dipping effort.
City might have been handed a lifeline from the penalty spot after a challenge on Albert Adomah by Nicky Bailey but referee Darren Drysdale waved play on, while substitute Ivan Sproule shot wide at the end of a purposeful run into the box.
But the result was put beyond doubt when Robson ended a mazy run with a shot that deflected past James and the home supporter's misery was complete when James was dismissed for a foul on substitute Cameron Park and Lita slotted the fourth.
Live text and stats
Saturday, 15 January 2011
Cisse (og) 43
Lita (pen) 90
01 James red card
20 Campbell-Ryce (Clarkson 79)
21 Cisse (Fontaine 65)
30 Stead (Sproule 65)
34 Pitman yellow card
02 Hoyte (McMahon 38)
26 A Taylor
18 O'Neil yellow card (Park 83)
09 Boyd (Emnes 62)
15 Lita yellow card
Ref: DrysdaleAtt: 13,699
Attempts on target
Attempts off target
90:00+3:09 The match has reached full-time.
90:00+1:52 Joe Bennett decides to take a short corner.
90:00+1:29 Free kick awarded for a foul by Ivan Sproule on Marvin Emnes. Direct free kick taken by Barry Robson. A cross is delivered
by Barry Robson, clearance made by Marvin Elliott.
90:00+1:04 The ball is crossed by Joe Bennett, Steven Caulker makes a clearance. Short corner taken by Marvin Emnes.
89:50 Foul by David James on Cameron Park, Penalty awarded.
89:50 GOAL - Leroy Lita:Bristol City 0 - 4 Middlesbrough Leroy Lita scores a penalty. Bristol City 0-4 Middlesbrough.
88:36 Sent off David James sent off.
86:49 The offside flag is raised against Albert Adomah. Free kick taken by Jason Steele.
84:42 Inswinging corner taken by Barry Robson, Lewin Nyatanga makes a clearance.
84:27 Marvin Emnes takes a shot. Blocked by Liam Fontaine.
82:42 Substitution Gary O'Neil leaves the field to be replaced by Cameron Park.
82:18 Albert Adomah takes a shot. Save by Jason Steele.
80:09 Barry Robson takes a shot. Liam Fontaine gets a block in.
78:26 Free kick awarded for an unfair challenge on Albert Adomah by Joe Bennett. Brett Pitman crosses the ball in from the free
78:26 Substitution David Clarkson comes on in place of Jamal Campbell-Ryce.
76:14 GOAL - Barry Robson:Bristol City 0 - 3 Middlesbrough Barry Robson fires in a goal from inside the box high into the middle of the goal. Bristol City 0-3 Middlesbrough.
75:51 Joe Bennett has a headed effort at goal from close range which goes wide of the left-hand upright.
73:05 Albert Adomah concedes a free kick for a foul on David Wheater. Direct free kick taken by Jason Steele.
72:39 Ivan Sproule delivers the ball.
71:50 Gary O'Neil challenges Ivan Sproule unfairly and gives away a free kick. Liam Fontaine takes the direct free kick.
71:50 Booking Gary O'Neil is cautioned.
68:20 Brett Pitman takes a shot from just inside the penalty box which clears the crossbar.
67:43 Marvin Elliott takes a shot from just inside the penalty box which clears the crossbar.
66:42 Free kick awarded for a foul by Albert Adomah on Tony McMahon. Barry Robson restarts play with the free kick.
66:10 The assistant referee flags for offside against Albert Adomah. Jason Steele restarts play with the free kick.
65:07 Shot from outside the penalty box by Leroy Lita goes wide right of the goal.
64:36 Substitution Kalifa Cisse goes off and Liam Fontaine comes on.
64:17 Substitution Jonathan Stead goes off and Ivan Sproule comes on.
61:08 Header from close range by Barry Robson misses to the right of the goal.
57:36 Booking Leroy Lita goes into the referee's book.
57:24 The assist for the goal came from Tony McMahon.
57:24 GOAL - Leroy Lita:Bristol City 0 - 2 Middlesbrough Leroy Lita finds the back of the net with a headed goal from close in. Bristol City 0-2 Middlesbrough.
55:18 The referee gives a free kick against Marvin Elliott for handball. Barry Robson crosses the ball in from the free kick, clearance
made by Steven Caulker. Nicky Bailey takes a shot. Blocked by Marvin Elliott.
54:20 Inswinging corner taken from the left by-line by Brett Pitman.
53:46 Jonathan Stead fouled by Matthew Bates, the ref awards a free kick. Free kick crossed right-footed by Lee Johnson, clearance
made by Matthew Bates.
51:20 Free kick awarded for an unfair challenge on Tony McMahon by Jonathan Stead. Jason Steele takes the direct free kick.
50:42 Tony McMahon takes a shot. David James makes a comfortable save.
48:29 Lee Johnson takes a shot from inside the box clearing the bar.
47:34 Marvin Elliott takes a shot. Save by Jason Steele.
45:35 Jonathan Stead is flagged offside by the assistant referee. Jason Steele restarts play with the free kick.
45:01 The referee gets the second half started.
45:00+2:03 The ref blows to end the first period.
45:00+0:51 Effort from the edge of the area by Brett Pitman goes wide of the left-hand upright.
42:05 Assist by Leroy Lita.
42:05 GOAL - Kalifa Cisse:Bristol City 0 - 1 Middlesbrough Own goal by Kalifa Cisse. Bristol City 0-1 Middlesbrough.
40:47 Jamal Campbell-Ryce crosses the ball, David Wheater makes a clearance.
40:20 Free kick awarded for a foul by David Wheater on Marvin Elliott. Lee Johnson takes the free kick.
37:34 Substitution Tony McMahon joins the action as a substitute, replacing Justin Hoyte.
35:10 Free kick awarded for an unfair challenge on Andrew Taylor by Brett Pitman. David Wheater takes the free kick.
35:10 Booking The referee cautions Brett Pitman for unsporting behaviour.
33:46 Unfair challenge on Jason Steele by Marvin Elliott results in a free kick. Free kick taken by Jason Steele.
33:18 Brett Pitman takes the inswinging corner, Kris Boyd manages to make a clearance.
33:11 Lee Johnson sends in a cross, clearance by David Wheater.
31:34 Barry Robson sends in a cross.
30:32 Centre by Gary O'Neil, clearance made by Steven Caulker.
29:12 Joe Bennett crosses the ball, save made by David James.
26:47 Steven Caulker is caught offside. Jason Steele takes the direct free kick.
25:05 The official flags Leroy Lita offside. Free kick taken by David James.
24:08 The ball is crossed by Jonathan Stead.
21:03 The ball is crossed by Andrew Taylor.
19:23 Andrew Taylor takes a shot. Clearance by Kalifa Cisse. Corner taken right-footed by Gary O'Neil to the near post, Marvin Elliott
manages to make a clearance.
16:11 Shot from long range by Jonathan Stead misses to the right of the target.
15:48 The assistant referee flags for offside against Leroy Lita. Lee Johnson takes the free kick.
14:47 Kris Boyd is ruled offside. David James restarts play with the free kick.
12:45 Brett Pitman has an effort at goal from long range that misses to the right of the target.
10:19 Kris Boyd is caught offside. Free kick taken by Lee Johnson.
9:47 Gary O'Neil takes the inswinging corner, Cole Skuse makes a clearance.
9:33 Gary O'Neil takes a shot. David James makes a save.
6:45 Jamal Campbell-Ryce decides to take the corner short.
6:39 Albert Adomah delivers the ball, Andrew Taylor makes a clearance.
5:08 Free kick awarded for a foul by Matthew Bates on Jonathan Stead. The free kick is delivered right-footed by Brett Pitman from
right wing, clearance by Kris Boyd.
3:12 Gary O'Neil takes a shot. Save by David James. Lee Johnson concedes a free kick for a foul on Leroy Lita. Free kick taken
by Matthew Bates.
0:00 The match gets underway.
Live text and data provided by The Press Association.
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