Robert Snodgrass and Grant Holt scored to set Norwich on their way to a win over a dreadful West Brom that takes them to safety.
Snodgrass opened the scoring with a rebound after Ben Foster saved from Wes Hoolahan midway through the first half.
Holt tapped in after Foster's error, Gareth McAuley scored an own goal and Jonny Howson curled in a fourth.
Norwich are six points above Wigan, who play struggling Aston Villa on the final day, and cannot be caught.
After a 4-3 win at Swansea and a 4-3 defeat to Manchester City in December, this was only the third time that Norwich have managed to score more than two goals in a Premier League game this season.
The fact their tally of 41 points cannot be reached by both the Latics and Villa means that Chris Hughton's side are safe with Queens Park Rangers and Reading already relegated.
This was a display that will have left Canaries fans wondering how their team was capable of a run of two wins in 19 that dropped them into trouble.
The imminent £8.5m arrival of Netherlands striker Ricky Van Wolfswinkel from Sporting Lisbon certainly signals a willingness to deal with a lack of goals that has been a key reason for their slump in 2013.
But there was no sign of a lack of cutting edge as Hughton's team pulled West Brom apart with their biggest win of the season.
Guaranteed a top-half finish, the Baggies, who have now suffered three straight defeats, simply had no match for the intensity of a home side that never looked inhibited by the significance of the occasion.
The visitors were cut open when Anthony Pilkington drifted in from the right flank and his firm effort was palmed down by Foster before Jonas Olsson hacked clear - but the breakthrough did come after 25 minutes.
Holt's cross from the right was headed down by Norwich centre-back Ryan Bennett.
Foster was quickly off his line to deny Hoolahan but Snodgrass squeezed a shot in to the top corner past Olsson for his seventh goal of the season.
West Brom goalkeeper Foster was tested again just before the interval when he pushed a fierce Hoolahan drive over the bar.
Baggies manager Steve Clarke signalled his frustration by putting on Billy Jones and Chris Brunt for Markus Rosenberg and Steven Reid at the break.
But Norwich continued to sweep forward and Holt added a second just after the hour thanks to an error from Foster.
The West Brom goalkeeper raced out to clear a Hoolahan through-ball but failed to make contact and Holt was able to stroll towards the empty net before tapping in.
Less than three minutes later, Hoolahan whipped in a free-kick from the right and the ball glanced off McAuley and into the corner of his own net.
It was a measure of West Brom's disappointing performance that Norwich goalkeeper John Ruddy, returning from more than five months out with a thigh problem, was not really tested until he held a Jones effort in the 72nd minute.
And in the final minute, Howson swapped passes with Luciano Becchio before bending a shot into the top corner.
Norwich manager Chris Hughton:
"It's a feeling of massive pride and we made life quite difficult in the second half of the season but that's an indication of how tough this league is. We have to fight for every win and were in a downward spiral we found it difficult to get out of.
"There was nerves and anxiety. We were desperate to stay in the Premier League and knew a win would make sure we retained our Premier League status and the way we went about it from the first minute was excellent.
"Being in the Premier League means everything and we're looking forward to next season."
West Brom manager Steve Clarke:
"We were very disappointing. From the off Norwich were on top of us, we couldn't get a foothold and were second best for most of the game.
"It was definitely the worst performance of the season by a considerable distance. It's now the kind of performance you associate West Brom with and we want better next week.
"They were sharper, brighter and had more energy from the first minute."
- 01 Ruddy
- 02 R Martin
- 05 Bassong
- 18 Garrido
- 24 R Bennett
- 04 Johnson
- 07 Snodgrass (Tettey - 76' )
- 08 Howson Booked
- 12 Pilkington
- 14 Hoolahan Booked (E Bennett - 77' )
- 09 Holt (Becchio - 86' )
- 28 Bunn
- 03 Whittaker
- 20 Barnett
- 17 E Bennett
- 27 Tettey
- 10 Jackson
- 19 Becchio
West Bromwich Albion
- 01 Foster
- 02 Reid (Jones - 46' )
- 03 Olsson Booked
- 04 Popov
- 23 McAuley
- 05 Yacob
- 07 Morrison
- 21 Mulumbu
- 08 Rosenberg (Brunt - 46' )
- 09 Long
- 20 Lukaku (Odemwingie - 80' )
- 13 Myhill
- 06 Ridgewell
- 28 Jones
- 30 Tamas
- 11 Brunt
- 17 Dorrans
- 24 Odemwingie
Live Text Commentary
Full Time The final whistle goes and the game is over.90:00 +1:16
Chris Brunt takes the inswinging corner, Russell Martin manages to make a clearance.89:04
Assist by Luciano Becchio.89:04 Goal scored
Goal! - Jonathan Howson - Norwich 4 - 0 West Brom Jonathan Howson gets on the score sheet with a goal from just inside the area to the top right corner of the goal. Norwich 4-0 West Brom.86:56
Free kick awarded for an unfair challenge on Peter Odemwingie by Bradley Johnson. Claudio Yacob takes the free kick.85:55
Elliott Bennett takes a inswinging corner to the near post, Goran Popov manages to make a clearance.85:41
Corner taken by Anthony Pilkington, Billy Jones manages to make a clearance.85:04 Substitution
Substitution Luciano Becchio replaces Grant Holt.82:44
Short corner worked by Anthony Pilkington.82:12
Anthony Pilkington takes a shot. Save by Ben Foster.81:06
Effort from just outside the box by Chris Brunt goes over the bar.80:02
Chris Brunt fouled by Grant Holt, the ref awards a free kick. Indirect free kick taken by Billy Jones.79:32 Substitution
Substitution Peter Odemwingie is brought on as a substitute for Romelu Lukaku.79:12
Chris Brunt takes a shot. Bradley Johnson gets a block in.75:33 Substitution
Substitution Wes Hoolahan goes off and Elliott Bennett comes on.75:33 Substitution
Substitution Alexander Tettey comes on in place of Robert Snodgrass.73:51
Shane Long takes a shot. Comfortable save by John Ruddy.72:41
Romelu Lukaku takes a shot. John Ruddy makes a comfortable save.71:06
Billy Jones takes a shot. Save by John Ruddy.69:59
Goran Popov takes the free kick.
Booking The referee cautions Wes Hoolahan for unsporting behaviour.69:53
Wes Hoolahan concedes a free kick for a foul on Shane Long.68:25
The referee blows for offside against Anthony Pilkington. Billy Jones takes the indirect free kick.67:02
Shot by Wes Hoolahan from deep inside the penalty area misses to the right of the goal.64:06
Assist on the goal came from Robert Snodgrass.64:06 Goal scored
Goal! - Gareth McAuley - Norwich 3 - 0 West Brom Gareth McAuley heads into his own net. Norwich 3-0 West Brom.63:44
James Morrison takes a shot. Save made by John Ruddy.63:14
Jonas Olsson gives away a free kick for an unfair challenge on Grant Holt. Free kick crossed right-footed by Robert Snodgrass, Gareth McAuley gets a block in.61:34
Wes Hoolahan provided the assist for the goal.61:34 Goal scored
Goal! - Grant Holt - Norwich 2 - 0 West Brom A goal is scored by Grant Holt from close in low into the middle of the goal. Norwich 2-0 West Brom.60:00
Header from deep inside the area by Grant Holt goes over the bar.53:43
Robert Snodgrass fouled by Youssouf Mulumbu, the ref awards a free kick. Jonathan Howson takes the indirect free kick.52:28
Grant Holt concedes a free kick for a foul on Claudio Yacob. Free kick taken by Ben Foster.51:36
Wes Hoolahan produces a right-footed shot from the edge of the box and misses to the right of the goal.50:39
Gareth McAuley gives away a free kick for an unfair challenge on Grant Holt. Robert Snodgrass takes the indirect free kick.49:05
The ball is delivered by Romelu Lukaku.47:28
Direct effort from the free kick comes in from Robert Snodgrass.47:28 Booking
Booking Jonas Olsson booked for unsporting behaviour.47:01
Grant Holt fouled by Jonas Olsson, the ref awards a free kick.45:51
Free kick awarded for a foul by Goran Popov on Robert Snodgrass. Russell Martin restarts play with the free kick.45:27
Romelu Lukaku produces a right-footed shot from deep inside the penalty box which goes wide of the left-hand post.45:01
The referee gets the second half underway.45:01 Substitution
Substitution Steven Reid leaves the field to be replaced by Billy Jones.45:01 Substitution
Substitution Chris Brunt on for Markus Rosenberg.45:00 +1:58 Half time
Half Time The referee blows for half time.45:00 +1:34 Booking
Booking Booking for Jonathan Howson for unsporting behaviour.45:00 +0:59
The referee blows for offside against Romelu Lukaku. John Ruddy takes the indirect free kick.44:52
Inswinging corner taken right-footed by Anthony Pilkington from the left by-line, clearance by Shane Long.41:37
The referee blows for offside against Wes Hoolahan. Indirect free kick taken by Ben Foster.41:11
Outswinging corner taken left-footed by Robert Snodgrass, clearance by Jonas Olsson.40:33
Shot from 30 yards by Wes Hoolahan. Save made by Ben Foster.38:41
Bradley Johnson challenges Youssouf Mulumbu unfairly and gives away a free kick. Free kick crossed right-footed by Steven Reid, brilliant save by John Ruddy.36:36
Free kick awarded for a foul by James Morrison on Russell Martin. Indirect free kick taken by John Ruddy.36:12
Markus Rosenberg takes a shot. Sebastien Bassong gets a block in.34:23
James Morrison takes a outswinging corner to the near post.34:14
Centre by Romelu Lukaku, clearance by Russell Martin.33:44
Robert Snodgrass concedes a free kick for a foul on Goran Popov. Indirect free kick taken by Jonas Olsson.32:33
Russell Martin sends in a cross, Goran Popov makes a clearance.31:51
Shane Long produces a cross.29:40
The ball is sent over by James Morrison, brilliant save by John Ruddy.28:56
The ball is delivered by Shane Long.25:05
Wes Hoolahan takes a shot. Ben Foster makes a save.24:40
Assist by Wes Hoolahan.24:40 Goal scored
Goal! - Robert Snodgrass - Norwich 1 - 0 West Brom Robert Snodgrass scores a goal from deep inside the penalty box high into the middle of the goal. Norwich 1-0 West Brom.23:59
Outswinging corner taken by Robert Snodgrass, Goran Popov manages to make a clearance.23:43
Anthony Pilkington takes a shot. Ben Foster makes a save.19:03
Markus Rosenberg is caught offside. John Ruddy takes the free kick.17:48
Goran Popov produces a cross, Ryan Bennett makes a clearance.16:36
James Morrison fouled by Jonathan Howson, the ref awards a free kick. Free kick taken by Goran Popov.15:50
The ball is crossed by Anthony Pilkington.14:51
Centre by Goran Popov, clearance by Ryan Bennett.11:39
Corner taken by Robert Snodgrass played to the near post, Grant Holt challenges Gareth McAuley unfairly and gives away a free kick. Ben Foster takes the free kick.6:52
The ball is swung over by Robert Snodgrass, Jonas Olsson makes a clearance.5:17
Free kick awarded for an unfair challenge on Markus Rosenberg by Wes Hoolahan. Markus Rosenberg takes the indirect free kick.4:24
Unfair challenge on Youssouf Mulumbu by Javier Garrido results in a free kick. Indirect free kick taken by Ben Foster.3:05
Outswinging corner taken by Robert Snodgrass from the left by-line, Shane Long makes a clearance.0:24
Unfair challenge on Anthony Pilkington by Jonas Olsson results in a free kick. Indirect free kick taken by Anthony Pilkington.0:00
The referee gets the game underway.
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