There will not be any final-day drama for Norwich City to endure. Chris Hughton can relax at last. His side's miserable run of form since the turn of the year had meant that relegation was a genuine concern, yet by the end of this match the mood of foreboding around Carrow Road had been replaced by a party atmosphere which few people could have seen coming before kick-off. Then all the talk had been of the manager's perceived negativity, Norwich's struggles in front of goal and trips to Doncaster and Bournemouth next season.

However Norwich knew that because Aston Villa and Wigan play each other next Sunday, a victory over West Bromwich would secure their safety so instead of freezing, they responded magnificently to the pressure. By the time Jonny Howson curled a wonderful fourth goal into Ben Foster's top-left corner from 25 yards in the 90th minute, the game had long been over as a contest.

This was Norwich's biggest victory in the Premier League since a 5-1 win at Everton in September 1993, only their third in the previous 20 matches and the first by more than one goal this season. They could not have chosen a better occasion to throw the shackles off.

"I thought we were excellent from the first minute to the 93rd minute," Hughton said later. "I'm incredibly relieved. We've embarked on a tough season. We've found it difficult since Christmas. On a day when it really counted it was arguably our best performance of the season. I must admit I didn't get much sleep last night and hopefully I won't get much tonight."

Sunday morning's comments by Grant Holt about Norwich's caution had done Hughton few favours and perhaps eager to dispel the doubts that have emerged over their style, City began feverishly, swarming all over the visitors and looking more like the side that went 10 games unbeaten in the winter. It helped, too, that West Bromwich seemed to take their cue from their supporters, who arrived armed with an impressive array of beach balls and inflatable animals.

While West Brom were thinking of the beach, Norwich's focus was undimmed and they made the breakthrough after 25 minutes. A minute after Anthony Pilkington had tested Foster with a stinging drive, Holt moved to the right flank and crossed towards Ryan Bennett, who nodded the ball into the six-yard box. Played onside by Jonas Olsson, Wes Hoolahan lunged at the ball and although Foster denied him, the rebound fell to Robert Snodgrass, whose finish soared into the roof of the net. It was a scrappy goal but one that lifted the tension and Norwich almost doubled their lead when Hoolahan's effort from 25 yards out was tipped over by Foster.

West Bromwich, unconvincing in their 4-3-3 formation, had offered no threat at all and John Ruddy, making his first start in goal for Norwich after six months out with a hip injury, was rarely extended. "We were really poor," said the head coach Steve Clarke, who expects to sell Peter Odemwingie this summer. "It was Norwich's day. I misread the game. I didn't think Norwich were capable of causing us so many problems."

Clarke tried to alter the flow of the match by replacing Markus Rosenberg with Chris Brunt at half-time, and Romelu Lukaku was soon scuffing wide from 12 yards out. He might have done better.

Yet Norwich remained in control and when Hoolahan tried to send Holt through after 62 minutes, Foster's comical miskick allowed Norwich's top scorer to run the ball into the empty net for his seventh of the season. The game was safe and so were Norwich.

Three minutes later, Gareth McAuley headed Snodgrass's free-kick into his own goal under pressure from Bennett and the celebrations could begin.

Man of the match Robert Snodgrass (Norwich City)