Brighton 0-1 West Ham
Kevin Nolan scored the only goal to move West Ham up to second in the Championship table and extend Brighton's winless run to seven games.
Gus Poyet's Brighton had much of the play at the Amex Stadium.
But Nolan took advantage of Liam Bridcutt's error to score from distance to put the visitors ahead.
The Seagulls, who saw Gary Dicker leave the pitch with an ankle injury in the second half, pushed for an equaliser but could not find a way through.
Sam Allardyce's team are now three points adrift of leaders Southampton, leaving Brighton with three points from a possible 21.
Nolan took only 16 minutes to deprive former Newcastle team-mate Steve Harper, who joined Brighton on a one-month loan deal on Monday, of a clean sheet.
The West Ham captain robbed Bridcutt in midfield and beat Harper with a curling effort from 25 yards to give the visitors the lead with his fourth goal of the season.
But other than a Nolan header that flew over the bar, Brighton were dominant for the rest of the opening period, with Craig Noone going close from distance and Craig Mackail-Smith forcing a smart save from Manuel Almunia.
The pressure continued after half-time without Almunia being tested, while John Carew's powerful shot on the turn was denied by Harper at the other end.
Almunia also had to be alert and brave to beat Mackail-Smith to Dicker's throughball.
Dicker left the field on a stretcher in the closing stages after receiving treatment for about five minutes for his injury.
Will Hoskins lifted a shot over the bar from just outside the area as Brighton desperately chased an equaliser.
But the Hammers came through eight minutes of injury time to hold on for a fourth away win, and fourth clean sheet, in seven away matches this season.
Brighton manager Gus Poyet:
"It was one mistake. We played the kind of football that if you make a mistake it will be expensive.
"But I'm proud and Brighton is back to its best, playing against a Premiership team and not letting them touch the ball for I don't know how long.
"It was one-way traffic. The whole game was the same, someone wants to play and go forward and someone wants to defend but unfortunately it didn't work with the result. Gary Dicker has an ankle problem but we will know more tomorrow."
West Ham manager Sam Allardyce:
"It was a disappointment to lose at Southampton, with them moving five points clear, but now we're back into second spot.
"Brighton made it hugely difficult but our defensive resilience, not just from the back four, was outstanding and it's a fantastic three points.
"Our defensive play was so good that it's hard to think of what chances Brighton had. They didn't have the chances to go with their possession."
Live Text Commentary
Full Time The final whistle goes and the game is over.90:00 +8:22
Effort on goal by Frederic Piquionne from just inside the area clears the crossbar.90:00 +6:33
Unfair challenge on Jack Collison by Gordon Greer results in a free kick. Direct free kick taken by Manuel Almunia.90:00 +6:10
Winston Reid challenges Craig Mackail-Smith unfairly and gives away a free kick. Free kick taken by Liam Bridcutt.90:00 +2:36 Substitution
Substitution Sam Baldock is brought on as a substitute for Julien Faubert.90:00 +1:42
Marcos Painter fouled by Mark Noble, the ref awards a free kick. Steve Harper takes the direct free kick.90:00 +1:10
Corner taken right-footed by Mark Noble.90:00 +1:00
Kevin Nolan takes a shot. Gordon Greer gets a block in.88:33
Free kick awarded for a foul by Craig Mackail-Smith on Freddie Sears. Manuel Almunia takes the free kick.87:53
Mark Noble takes a short corner.87:34
Julien Faubert takes a shot. Gordon Greer makes a clearance.86:15
Will Hoskins takes a shot from just inside the penalty box which clears the crossbar.84:34
Inswinging corner taken by Craig Noone from the right by-line, Kevin Nolan manages to make a clearance.81:50 Substitution
Substitution Gary Dicker goes off and Ryan Harley comes on.76:19
Direct free kick taken by Mark Noble.76:19 Booking
Booking Liam Bridcutt receives a caution for unsporting behaviour.76:12
Jack Collison fouled by Liam Bridcutt, the ref awards a free kick.69:22
Manuel Almunia takes the free kick.69:22 Substitution
Substitution (Brighton) makes a substitution, with Will Buckley coming on for Matthew Sparrow.69:22
Foul by Craig Mackail-Smith on Manuel Almunia, free kick awarded.
Freddie Sears has a shot on goal from outside the area which misses left.64:23 Substitution
Substitution Frederic Piquionne replaces John Carew.64:12
Liam Bridcutt takes a shot from a long way out which goes wide of the right-hand upright.63:00
Handball decision goes against Julien Faubert. Gordon Greer takes the direct free kick.60:38
Inswinging corner taken from the right by-line by Craig Noone, clearance made by Julien Faubert.59:08
Craig Mackail-Smith has shot on goal from just outside the area which goes wide of the right-hand upright.58:15 Substitution
Substitution (Brighton) makes a substitution, with Will Hoskins coming on for Ashley Barnes.58:08
Craig Mackail-Smith has an effort at goal from just outside the box which goes wide of the right-hand post.56:49
John Carew takes a shot. Save by Steve Harper.55:55
Mark Noble takes the direct free kick.55:55 Booking
Booking Lewis Dunk is shown a yellow card for unsporting behaviour.55:50
Free kick awarded for a foul by Lewis Dunk on Freddie Sears.53:31 Substitution
Substitution Freddie Sears joins the action as a substitute, replacing Papa Bouba Diop.52:42
Inswinging corner taken by Craig Noone from the right by-line.50:33
Unfair challenge on Craig Noone by Papa Bouba Diop results in a free kick. Shot on goal comes in from Ashley Barnes from the free kick.49:35
Free kick awarded for an unfair challenge on Lewis Dunk by John Carew. Lewis Dunk restarts play with the free kick.48:14
Jack Collison gives away a free kick for an unfair challenge on Gonzalo Jara Reyes. Gonzalo Jara Reyes takes the direct free kick.47:56
John Carew gives away a free kick for an unfair challenge on Marcos Painter. Free kick taken by Marcos Painter.46:36
Craig Noone takes a inswinging corner to the near post, clearance by John Carew.45:53
Inswinging corner taken from the right by-line by Craig Noone.45:01
The second half has started.45:00 +2:01 Half time
Half Time The ref blows to signal half-time.45:00 +1:28
Craig Mackail-Smith takes a shot. Save made by Manuel Almunia.44:48
Marcos Painter gives away a free kick for an unfair challenge on Mark Noble. Mark Noble takes the free kick.43:45
Craig Noone produces a left-footed shot from just outside the box that goes wide right of the target.43:12
Inswinging corner taken by Craig Noone.41:46
Corner taken left-footed by Craig Noone from the right by-line, Kevin Nolan makes a clearance.41:13
Corner taken short by Craig Noone.40:06
Outswinging corner taken by Craig Noone.39:46
Liam Bridcutt takes a shot. John Carew manages to make a clearance.39:21
Short corner worked by Craig Noone.38:16
Free kick awarded for an unfair challenge on Julien Faubert by Gary Dicker. Mark Noble takes the free kick.37:38
Close range headed effort by Ashley Barnes misses to the right of the target.37:02
Corner taken left-footed by Craig Noone from the right by-line to the near post, clearance made by John Carew.36:07
Header on goal by Kevin Nolan from inside the box goes harmlessly over the target.35:18
Mark Noble takes the free kick.35:18 Booking
Booking Gordon Greer booked for unsporting behaviour.35:11
Gordon Greer gives away a free kick for an unfair challenge on John Carew.34:18
John Carew concedes a free kick for a foul on Lewis Dunk. Gordon Greer takes the direct free kick.28:10
Matthew Sparrow takes a shot. Manuel Almunia makes a save.27:12
Winston Reid gives away a free kick for an unfair challenge on Craig Mackail-Smith. Gary Dicker restarts play with the free kick.26:59
Papa Bouba Diop concedes a free kick for a foul on Matthew Sparrow. Free kick taken by Gonzalo Jara Reyes.21:20
Effort on goal by Craig Noone from long range goes harmlessly over the bar.19:43
Steve Harper restarts play with the free kick.19:43 Booking
Booking Julien Faubert booked.19:29
Julien Faubert concedes a free kick for a foul on Marcos Painter.16:45 Goal scored
Goal! - Kevin Nolan - Brighton 0 - 1 West Ham Kevin Nolan gets on the score sheet with a goal from just inside the penalty area to the bottom left corner of the goal. Brighton 0-1 West Ham.14:34
Julien Faubert fouled by Marcos Painter, the ref awards a free kick. Mark Noble restarts play with the free kick.12:34
George McCartney takes the free kick.12:34 Booking
Booking The referee cautions Gonzalo Jara Reyes for unsporting behaviour.12:24
Free kick awarded for a foul by Gonzalo Jara Reyes on Mark Noble.10:18
Free kick awarded for a foul by Matthew Sparrow on Jack Collison. George McCartney takes the free kick.6:14
Effort from inside the area by Craig Mackail-Smith misses to the left of the target.5:47
Foul by John Carew on Lewis Dunk, free kick awarded. Free kick taken by Steve Harper.1:45
Unfair challenge on Papa Bouba Diop by Gonzalo Jara Reyes results in a free kick. Winston Reid restarts play with the free kick.0:00
The match has kicked off.
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