Shane Long marked his return from injury with the winner to lift West Brom into the top 10 and pile the problems on for Bolton.
The Baggies had gone into an early lead when Jerome Thomas beat the offside trap and rounded Jussi Jaaskelainen.
Ivan Klasnic levelled from the spot after Fabrice Muamba was fouled.
But Long headed his fourth goal of the season in the 56th minute, just four weeks after sustaining a serious-looking knee injury.
With both sides desperate for points to pull clear of the relegation zone, it was a lively start.
Chris Eagles saw his dipping volley fly narrowly over the bar and Gary Cahill had a header cleared off the line by Youssouf Mulumbu, while, at the other end Jonas Olsson and Long both went close.
Thomas was proving to be a real menace down the flanks, and it was no surprise when he put the Baggies into the lead.
Zoltan Gera's pass beat Bolton's offside trap and Thomas was on hand to fire past Jaaskelainen.
Did you know?
- Owen Coyle has never managed a side to victory against a Roy Hodgson team in five attempts
The former Arsenal winger was soon back in the thick of the action - but at the other end of the pitch.
His clumsy foul on Muamba was punished with a penalty and Klasnic calmly converted for his third goal in two games.
Both sides had chances to go into the half-time break in front, but Mark Davies failed to add a finishing touch to his mazy run and Gera could only head straight at Jaaskelainen.
The home side started to apply more pressure in the second half and it came as no surprise when they went back into the lead.
Thomas fed Nicky Shorey, who sent in a fantastic cross for Long to cap his amazing return from injury - just four weeks after chipping a bone in his knee following a controversial challenge from Aston Villa's Alan Hutton .
Bolton brought on Martin Petrov and David Ngog in an attempt to wrestle back the initiative but they too struggled to make any impact on a solid home defence.
Roy Hodgson's men were in complete control, with Thomas, Long and Gera linking up to great effect throughout the second half.
And they might have made the victory more convincing in stoppage time, but Mark Davies was spared embarrassment when he deflected a shot narrowly wide of the post.
Hodgson, speaking before the match, suggested this fixture would go a long way to deciding whether his side would challenge in the top half or be battling relegation.
On the evidence of this performance, it will be the former with Owen Coyle's men seemingly destined for a long season.
West Brom manager Roy Hodgson
"Shane Long and Zoltan Gera were excellent for us. It was a one-sided game and I think we were more than good value for the three points.
"We produced a performance we knew we were capable of.
"We were very solid defensively and we piled up chances at the other end."
Bolton manager Owen Coyle
"The game looked evenly poised at half-time but we were not at the same level in the second half.
"The game was there to win, and we had a platform to at least get a draw, but we left with nothing and that is disappointing.
"At 2-1 we were chasing the game and, as much as we pushed on, we didn't create the type of chances we did in the first half."
Live Text Commentary
Full Time The final whistle is blown by the referee.90:00 +3:15
Corner taken short by Zoltan Gera.90:00 +1:21 Substitution
Substitution (West Brom) makes a substitution, with Simon Cox coming on for Youssouf Mulumbu.87:18
The ball is delivered by Nicky Shorey, David Wheater makes a clearance.84:33
Youssouf Mulumbu challenges David Ngog unfairly and gives away a free kick. Free kick taken by Paul Robinson.83:09
Gary Cahill gives away a free kick for an unfair challenge on Shane Long. Nicky Shorey restarts play with the free kick.82:08
Free kick awarded for a foul by David Ngog on Nicky Shorey. Jonas Olsson restarts play with the free kick.80:19
Nicky Shorey restarts play with the free kick.80:19 Substitution
Substitution Fabrice Muamba goes off and Gael Kakuta comes on.80:19
Free kick awarded for an unfair challenge on Zoltan Gera by Fabrice Muamba.79:29 Substitution
Substitution (West Brom) makes a substitution, with Graham Dorrans coming on for Jerome Thomas.77:52
Foul by Zoltan Gera on Nigel Reo-Coker, free kick awarded. Fabrice Muamba restarts play with the free kick.76:53
Ivan Klasnic takes a shot. Save by Ben Foster.76:14
Effort on goal by Zoltan Gera from just inside the area clears the crossbar.76:08
The ball is crossed by Jerome Thomas, Gary Cahill makes a clearance.74:37
The ball is delivered by Zoltan Gera, clearance by Gary Cahill.72:09
Jerome Thomas produces a cross, Gary Cahill makes a clearance.71:02
Zoltan Gera takes a shot from inside the box clearing the bar.69:17 Substitution
Substitution (Bolton) makes a substitution, with David Ngog coming on for Kevin Davies.68:55 Substitution
Substitution (Bolton) makes a substitution, with Martin Petrov coming on for Chris Eagles.
The ball is delivered by James Morrison, Gareth McAuley takes a shot. Save by Jussi Jaaskelainen.64:06
Chris Brunt takes a outswinging corner from the left by-line played to the near post.62:15
Jerome Thomas takes a shot. Save by Jussi Jaaskelainen.60:56
Effort on goal by Youssouf Mulumbu from outside the area goes harmlessly over the bar.59:29
Effort on goal by Kevin Davies from deep inside the penalty area misses to the right of the goal.58:44
Jerome Thomas crosses the ball, Jussi Jaaskelainen makes a save.58:29
David Wheater gives away a free kick for an unfair challenge on Shane Long. Free kick taken by Steven Reid.57:17
Handball by Shane Long. Jussi Jaaskelainen takes the direct free kick.55:39
Assist by Nicky Shorey.55:39 Goal scored
Goal! - Shane Long - West Brom 2 - 1 Bolton Shane Long grabs a headed goal from deep inside the penalty box. West Brom 2-1 Bolton.55:36
Nicky Shorey produces a cross,54:10
Zoltan Gera sends in a cross, clearance by David Wheater. Corner taken left-footed by Chris Brunt to the near post, Jonas Olsson takes a shot. Blocked by Gary Cahill. Chris Brunt takes the outswinging corner, clearance made by Paul Robinson.53:15
Effort on goal by Jerome Thomas from deep inside the area goes harmlessly over the bar.52:49
Zoltan Gera produces a cross, Jerome Thomas takes a shot. Blocked by Fabrice Muamba.52:38
Nicky Shorey crosses the ball, clearance made by Gary Cahill.51:50
Inswinging corner taken from the right by-line by Chris Brunt. The ball is delivered by Jerome Thomas. Chris Brunt delivers the ball, David Wheater manages to make a clearance.51:18
James Morrison takes a shot. Blocked by Gary Cahill.47:34
Nigel Reo-Coker challenges Jerome Thomas unfairly and gives away a free kick. Free kick taken by James Morrison.46:15
Free kick awarded for a foul by Paul Robinson on Youssouf Mulumbu. Direct free kick taken by Steven Reid.45:24
Kevin Davies crosses the ball, Steven Reid makes a clearance.45:01
The second half kicks off.45:00 +1:24 Half time
Half Time The first half comes to an end.45:00 +1:06
Chris Eagles takes a shot. Steven Reid gets a block in.45:00 +0:31
Centre by Nicky Shorey, Zoltan Gera takes a shot. Save made by Jussi Jaaskelainen.42:32
Steven Reid challenges Kevin Davies unfairly and gives away a free kick. Paul Robinson restarts play with the free kick.41:10
Unfair challenge on Gareth McAuley by Kevin Davies results in a free kick. Free kick taken by Ben Foster. Mark Davies challenges Jerome Thomas unfairly and gives away a free kick. Free kick taken by Chris Brunt.38:58
Corner taken by Chris Eagles played to the near post, Kevin Davies takes a shot. Corner taken by Chris Eagles from the left by-line, blocked by Jonas Olsson. Jonas Olsson makes a clearance.38:31
Mark Davies takes a shot. Save by Ben Foster.36:57
Free kick awarded for an unfair challenge on Chris Eagles by Chris Brunt. Paul Robinson takes the free kick.35:51
Foul by Ivan Klasnic on Steven Reid, free kick awarded. Free kick taken by James Morrison.34:56
Ivan Klasnic crosses the ball, Ben Foster makes a save.34:18
Jerome Thomas concedes a free kick for a foul on Mark Davies. Jussi Jaaskelainen restarts play with the free kick.32:49
Free kick awarded for an unfair challenge on Kevin Davies by Steven Reid. Direct free kick taken by Ivan Klasnic. Chris Eagles takes a shot. Shane Long gets a block in.30:34
Shane Long is flagged offside by the assistant referee. Direct free kick taken by Jussi Jaaskelainen.29:34
The ball is crossed by Jerome Thomas, David Wheater manages to make a clearance.29:08
Unfair challenge on Jonas Olsson by Ivan Klasnic results in a free kick. Direct free kick taken by Ben Foster.28:32
Shane Long concedes a free kick for a foul on Nigel Reo-Coker. Free kick taken by Jussi Jaaskelainen.27:31
Nigel Reo-Coker sends in a cross, save by Ben Foster.27:03
Direct free kick taken by Paul Robinson.27:03 Booking
Booking Caution for Jerome Thomas.26:54
Free kick awarded for a foul by Jerome Thomas on Fabrice Muamba.23:34
Gareth McAuley gives away a free kick for an unfair challenge on Ivan Klasnic. Chris Eagles takes the direct free kick.22:31
Jonas Olsson concedes a free kick for a foul on Kevin Davies. Free kick taken by Joe Riley.22:14
Kevin Davies delivers the ball, Ben Foster makes a save.20:45
Assist on the goal came from Fabrice Muamba.20:45 Goal scored
Goal! - Ivan Klasnic - West Brom 1 - 1 Bolton Ivan Klasnic scores a power penalty. West Brom 1-1 Bolton.19:57
Jerome Thomas concedes a Penalty for a foul on Fabrice Muamba.19:35
Inswinging corner taken from the left by-line by Chris Eagles, clearance by Gareth McAuley.19:04
Shane Long challenges Gary Cahill unfairly and gives away a free kick. Direct free kick taken by Jussi Jaaskelainen.15:48
Assist by Zoltan Gera.15:48 Goal scored
Goal! - Jerome Thomas - West Brom 1 - 0 Bolton Jerome Thomas fires in a goal from inside the six-yard box to the bottom right corner of the goal. West Brom 1-0 Bolton.15:01
Kevin Davies concedes a free kick for a foul on Jonas Olsson. Nicky Shorey takes the direct free kick.14:20
Shane Long takes a shot. Blocked by Chris Eagles.13:32
Centre by Ivan Klasnic, Ben Foster makes a save.10:27
The referee gives a free kick against Shane Long for handball. Jussi Jaaskelainen restarts play with the free kick.9:52
The ball is sent over by Zoltan Gera.7:34
Nigel Reo-Coker concedes a free kick for a foul on Shane Long. Chris Brunt takes the free kick.6:35
The ball is swung over by Nicky Shorey, Headed from the edge of the area by Zoltan Gera goes wide of the left-hand upright.5:12
Chris Eagles takes a outswinging corner from the right by-line to the near post, Gary Cahill takes a shot. Youssouf Mulumbu makes a clearance.4:24
Shot from outside the box by James Morrison misses to the left of the goal.4:17
Chris Brunt crosses the ball, clearance by Joe Riley.3:13
James Morrison takes a outswinging corner.2:39
Chris Brunt takes the outswinging corner, Jonas Olsson takes a shot. Save by Jussi Jaaskelainen.2:07
Nigel Reo-Coker handles the ball and concedes a free kick. Chris Brunt takes the free kick. Jerome Thomas crosses the ball, Joe Riley makes a clearance.1:32
Shot by Chris Eagles from just outside the area goes over the net.1:09
The ball is swung over by Joe Riley.0:39
The ball is delivered by Joe Riley, Nicky Shorey gets a block in. Corner taken by Chris Eagles played to the near post, Shane Long manages to make a clearance.0:00
The game gets underway.
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