Ricardo Vaz Te and Gary O'Neil both scored to help strengthen West Ham's automatic promotion hopes.
Vaz Te broke the deadlock after a goalless first half at London Road when he headed home a Matt Taylor cross.
O'Neil's curling effort from 25 yards sealed an 11th away win for Sam Allardyce's side.
West Ham move one point behind second-placed Reading with seven games remaining, while Peterborough have lost five of their last seven.
The home side started brightly with Paul Taylor's powerful shot rattling the bar.
West Ham's 11 away wins
13 Aug: Doncaster 1-0
16 Aug: Watford 4-0
28 Aug: Nottingham Forest 4-1
24 Oct: Brighton 1-0
05 Nov : Hull 2-0
19 Nov: Coventry 2-1
29 Nov: Middlesbrough 2-0
14 Jan: Portsmouth 1-0
21 Feb: Blackpool 4-1
04 Mar: Cardiff 2-0
27 Mar: Peterborough 2-0
West Ham struggled for long periods, but were much sharper after the interval, and they took the lead in the 52nd minute when Vaz Te connected with Taylor's cross.
It went from bad to worse for Peterborough six minutes later.
Former Middlesbrough player O'Neil decided to try his luck from 25 yards and, to the delight of West Ham's 5,000 travelling fans, the ball flew past Paul Jones into the net.
West Ham were denied a third when Kevin Nolan hit the woodwork before Peterborough's Lee Frecklington was frustrated by an excellent Rob Green save.
However, the visitors finished strongly with Nolan, Carlton Cole, George McCartney and Vaz Te all going close.
West Ham manager Sam Allardyce on fans' chants criticising their style of play: "The perception of some people is deluded as the facts about my teams clearly speak for themselves.
"It is a tag that has followed me around for a long time and one I'm never going to be able to shift. I can't do anything about that but I can win football matches.
"We have had to overcome home teams playing with a lot of energy in front of full houses throughout this season. We did it again here and once we got the goals, we out-passed and outplayed Peterborough.
"It was a good performance, although not as good as at Burnley on Saturday. We only drew that game though so everyone was miserable whereas they will be happy tonight."
Peterborough manager Darren Ferguson: "We paid the price for not scoring when we were having the better of the game. If George [Boyd] had taken that chance right on the stroke of half-time, I feel sure we would have gone on to win.
"We should have had a penalty just before that and I feel sure it would have been given had it happened in the other area, but the really disappointing thing was the way in which we reacted to going behind.
"Too many players went into their shells and you can't afford to do that against any team, let alone one aiming to return to the Premier League."
- 28 Jones
- 05 Zakuani (Little - 62' )
- 18 Brisley
- 27 Alcock
- 11 McCann
- 14 Rowe
- 23 Frecklington (Kearns - 88' )
- 08 Tomlin (Sinclair - 62' Booked )
- 10 Boyd
- 20 Barnett
- 26 Taylor
- 01 Lewis
- 02 Little
- 21 Kearns
- 09 Ball
- 12 Sinclair
West Ham United
- 01 Green
- 03 McCartney
- 05 Tomkins
- 15 Faye (Collins - 46' )
- 17 O'Brien (Faubert - 46' )
- 04 Nolan
- 14 Taylor
- 16 Noble
- 32 O'Neil (Maynard - 88' )
- 09 Cole
- 12 Vaz Te
- 18 Faubert
- 25 Collins
- 07 Baldock
- 08 Maynard
- 11 Carew
Live Text Commentary
Full Time The match has reached full-time.90:00 +2:28
Ricardo Vaz Te takes a shot. Save made by Paul Jones.90:00 +1:18
Danny Collins gives away a free kick for an unfair challenge on Tyrone Barnett. Grant McCann takes the direct free kick.90:00 +0:12
Ricardo Vaz Te takes a shot. Save by Paul Jones. Matthew Taylor has an effort at goal from the edge of the area that misses to the right of the target.87:05 Substitution
Substitution Daniel Kearns replaces Lee Frecklington.87:05 Substitution
Substitution Gary O'Neil leaves the field to be replaced by Nicky Maynard.87:05
Centre by Julien Faubert, Tommy Rowe makes a clearance.85:01
George McCartney takes a shot. Save made by Paul Jones.83:47
Carlton Cole takes a shot. Save by Paul Jones. Outswinging corner taken left-footed by Matthew Taylor, Mark Little manages to make a clearance.81:00
A cross is delivered by Ricardo Vaz Te, clearance made by Shaun Brisley.79:23
The ball is delivered by Julien Faubert.78:02
Corner taken left-footed by Matthew Taylor, Paul Jones makes a save.75:00
A cross is delivered by Gary O'Neil.73:55
A cross is delivered by Julien Faubert.73:17
Ricardo Vaz Te has an effort at goal from outside the penalty box missing to the wide right of the target.72:37
Grant McCann takes a shot.70:30 Booking
Booking Emile Sinclair receives a yellow card.68:51
Free kick awarded for an unfair challenge on Craig Alcock by Carlton Cole. Direct free kick taken by Craig Alcock.66:53
Kevin Nolan takes a shot.65:18
Lee Frecklington takes a shot. Save by Robert Green. Outswinging corner taken by Grant McCann from the left by-line, Emile Sinclair challenges Danny Collins unfairly and gives away a free kick. Robert Green takes the direct free kick.
Centre by Matthew Taylor, clearance by Craig Alcock. Inswinging corner taken right-footed by Mark Noble from the left by-line, save by Paul Jones.63:08
Centre by Julien Faubert, Craig Alcock gets a block in. Corner taken short by Matthew Taylor.61:16 Substitution
Substitution Lee Tomlin goes off and Emile Sinclair comes on.61:16 Substitution
Substitution Mark Little comes on in place of Gabriel Zakuani.60:17
Kevin Nolan has shot on goal from just outside the penalty box which goes wide of the right-hand upright.56:06
Assist by Kevin Nolan.56:06 Goal scored
Goal! - Gary O'Neil - Peterboro 0 - 2 West Ham Goal scored by Gary O'Neil from outside the penalty area to the bottom left corner of the goal. Peterborough 0-2 West Ham.54:46
Kevin Nolan produces a left-footed shot from the edge of the area and misses to the left of the goal.54:02
Craig Alcock delivers the ball, save made by Robert Green.52:18
Foul by James Tomkins on Tyrone Barnett, free kick awarded. Free kick crossed by Lee Tomlin, clearance by Kevin Nolan.50:59
The assist for the goal came from Matthew Taylor.50:59 Goal scored
Goal! - Ricardo Vaz Te - Peterboro 0 - 1 West Ham Ricardo Vaz Te scores a headed goal from close range. Peterborough 0-1 West Ham.50:44
Julien Faubert delivers the ball, clearance made by Grant McCann.49:31
Centre by George McCartney, Gary O'Neil challenges Grant McCann unfairly and gives away a free kick. Free kick taken by Paul Jones.47:54
The ball is delivered by George McCartney, clearance made by Gabriel Zakuani.47:25
The ball is sent over by Ricardo Vaz Te, clearance made by Grant McCann.45:01
The match restarts for the second half.45:01 Substitution
Substitution Julien Faubert on for Joey O'Brien.45:01 Substitution
Substitution (West Ham) makes a substitution, with Danny Collins coming on for Abdoulaye Faye.45:00 +4:58 Half time
Half Time The whistle is blown to end the first half.45:00 +0:57
Lee Tomlin crosses the ball, George Boyd takes a shot. Blocked by James Tomkins. Short corner taken by Paul Taylor, Shot from just outside the box by Lee Tomlin misses to the right of the target.44:57
A cross is delivered by Gary O'Neil, George Boyd gets a block in. Corner taken by Matthew Taylor from the right by-line to the near post, clearance made by Tyrone Barnett.43:31
Paul Taylor produces a left-footed shot from just outside the area that goes wide left of the goal.41:58
Free kick awarded for an unfair challenge on James Tomkins by Paul Taylor. Direct free kick taken by Abdoulaye Faye.41:31
The ball is swung over by Ricardo Vaz Te, Gabriel Zakuani manages to make a clearance.41:27
The ball is sent over by Matthew Taylor.38:28
Unfair challenge on Tommy Rowe by Ricardo Vaz Te results in a free kick. Direct free kick taken by Grant McCann.37:53
Ricardo Vaz Te takes a shot. Blocked by Shaun Brisley.36:52
Mark Noble takes a shot. Gabriel Zakuani gets a block in. Inswinging corner taken from the right by-line by Matthew Taylor, Tyrone Barnett manages to make a clearance.33:48
Shot on goal by Matthew Taylor from just inside the area goes over the target.33:23
The ball is sent over by Ricardo Vaz Te, blocked by George Boyd. Corner taken by Matthew Taylor from the right by-line.32:07
Shot from just outside the area by Matthew Taylor goes over the bar.31:19
Ricardo Vaz Te delivers the ball, clearance by Shaun Brisley.29:29
A cross is delivered by George Boyd.28:24
Paul Taylor produces a right-footed shot from outside the penalty box and misses right.26:38
Centre by Ricardo Vaz Te, blocked by Tommy Rowe. Inswinging corner taken left-footed by Matthew Taylor from the right by-line to the near post, clearance made by Grant McCann.25:15
Shot from 20 yards by Lee Frecklington. Blocked by Joey O'Brien.23:45
Unfair challenge on Lee Tomlin by Carlton Cole results in a free kick. Grant McCann takes the free kick.23:07
Centre by Matthew Taylor, Paul Jones makes a save.22:20
Unfair challenge on George McCartney by Lee Tomlin results in a free kick. The free kick is swung in right-footed by Mark Noble.21:21
Matthew Taylor sends in a cross, James Tomkins produces a header from deep inside the six-yard box which goes wide of the right-hand upright.20:31
Inswinging corner taken left-footed by Matthew Taylor from the right by-line to the near post, clearance made by Tommy Rowe.19:19
Shot by Mark Noble. Save made by Paul Jones.18:04
A cross is delivered by George McCartney, Paul Jones makes a save.17:18
Shot from 35+ yards by George Boyd. Robert Green makes a comfortable save.15:53
George Boyd fouled by Ricardo Vaz Te, the ref awards a free kick. Free kick crossed by Grant McCann, Carlton Cole makes a clearance.15:43
Effort from 25 yards by Tommy Rowe. James Tomkins gets a block in.15:37
The ball is crossed by Craig Alcock, clearance made by James Tomkins.14:04
Ricardo Vaz Te takes a shot. Save by Paul Jones.12:34
Foul by James Tomkins on Paul Taylor, free kick awarded. Free kick taken by Grant McCann.11:06
Carlton Cole concedes a free kick for a foul on Shaun Brisley. Paul Jones restarts play with the free kick.10:48
The ball is sent over by Joey O'Brien, clearance made by Craig Alcock.9:32
Paul Taylor takes a shot. Lee Frecklington takes a shot. Robert Green makes a save.8:23
The assistant referee signals for offside against Tyrone Barnett. Indirect free kick taken by Robert Green.3:48
The ball is sent over by Matthew Taylor, Paul Jones makes a save.3:29
The ball is crossed by Gary O'Neil, Shaun Brisley manages to make a clearance.3:07
Kevin Nolan delivers the ball, Gabriel Zakuani manages to make a clearance.2:22
Gabriel Zakuani concedes a free kick for a foul on Gary O'Neil. Mark Noble takes the direct free kick.0:21
Lee Tomlin takes a shot. Save by Robert Green.0:00
The ref blows the whistle to start the match.
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