It threatened to be a miserable day for Rickie Lambert. With Roy Hodgson in the stands weighing up his options for Brazil, Lambert found himself dumped on the bench. But in the space of 40 second-half minutes, the England hopeful produced a stellar display to reignite his World Cup hopes and propel Southampton to a win – albeit one they almost conspired to toss away in remarkable fashion.

Lambert scored after barely 60 seconds of his arrival. In fact, he didn't just score, he waltzed his way past the last defender before opening his body and slotting the ball inside the near post, showing the kind of composure and dexterity that could be invaluable to England at the World Cup.

"I thought coming on as a substitute would be good for him," said Mauricio Pochettino afterwards, with a wry smile. Indeed it was.

Southampton had taken the lead after five minutes when a speedy, one-touch interchange on the right flank led to Gaston Ramírez threading a weighted ball into Morgan Schneiderlin's path and, without a defender in sight, he clipped a confident finish beyond the keeper. The dummy run from Jay Rodriguez, who claimed his first England cap last November, was fundamental in creating the avenue of space. "We are Southampton, we're off to Brazil!" chanted the delighted home fans.

Norwich looked overwhelmed by the pace and fluidity of Southampton's early play. Even after making five changes to the side that drew 1-1 with Stoke last weekend, they lacked punch. Steven Whittaker, Jonny Howson, Gary Hooper and Anthony Pilkington – all substitutes in that match – were given starts, while Ryan Bennett also came in after a hamstring injury. Norwich attacks were so rare in the first half that Hooper, a lone striker, scarcely saw the ball. When he was given a rare chance inside the box, he flashed a shot wide.

Hodgson, who will announce his provisional 30-man England squad for the World Cup on 13 May, might have been bemused when Adam Lallana was withdrawn in a tactical switch very early in the second half. But Lambert, his replacement, soon collected a bouncing ball and turned the last defender, Joseph Yobo, to make it 2-0; he made a tough chance look like a bread-and-butter finish.

Chris Hughton made a triple substitution, bringing on Ricky van Wolfswinkel, Nathan Redmond and Johan Elmander, only to be pilloried by the visiting fans with chants of: "You don't know what you're doing." With just two goals between the trio in the league this season, it was not a move that appeared to spell danger. Instead, Southampton bagged a third goal. Lambert was this time the creator, unselfishly laying off for the impressive Rodriguez to score from close range after Guly do Prado's initial effort had been blocked.

But then the game unexpectedly flipped as Southampton gifted Norwich two goals in quick succession with horrendously misplaced passes. First, José Fonte laid on Elmander for a one-on-one which he dispatched, then Robert Snodgrass found the net from a tight angle after a mistake by Do Prado.

"It flattered us," admitted Hughton, whose tenure remains in doubt. "I understand the chants directed at me because for the majority of the game a very good Southampton team were better than us. We gave ourselves a mountain to climb."

It was an embarrassing conclusion to a match Southampton had bossed, but Sam Gallagher's stoppage-time goal ended things on a high for the Saints.