Simeon Jackson was the City hero with a second-half header to sink Portsmouth 1-0 and secure second place in the npower Championship.
Cardiff’s home defeat by Middlesbrough earlier in the day meant Norwich kicked off knowing a win on the south coast would ensure they went up with a game to spare.
And their jubilant fans spilled onto the pitch at the final whistle to celebrate with the players and club shareholder, and chief cheerleader, Delia Smith on a memorable night for the Norfolk club.
Lambert said: “It’s incredible what the lads have done. They are the ones who do it week in week out
“In the two years we have been here it’s a miracle what has happened.
“And it’s how we’ve done it, from League One and then the Championship. It’s up there with anything I’ve done.”
City dropped out of the Premier League six years ago and hit rock-bottom when they were at the foot of League One on the opening day of last season following a 7-1 defeat by Colchester.
Their reaction to that hammering was to promptly hire the opposition manager, and just 20 months later Lambert’s Norwich are the first team to achieve successive promotions to reach the top flight since Manchester City in 2000.
Skipper Grant Holt, who has spearheaded the promotion push with 22 goals, was full of praise for the Scottish boss.
“The manager has been fantastic. He’s a motivator and has been great for us,” he said. “We’ve got a fantastic bunch of lads here. It’s a joy being with each other every day.”
Jackson struck in the 50th minute when he buried David Fox’s superb cross.
It was a ninth goal in seven matches for the striker, formerly of Rushden and Gillingham, who will now be lining up against Manchester United and Chelsea next season.
Jackson said: “It’s been a magnificent effort by everyone.
“It’s not down to me, its down to everyone throughout the season. I cant believe we’ve done it.”
* In the Scottish Premier League Mickael Antoine-Curier got the winner as Hamilton beat relegation rivals St Mirren 1-0.
PORTSMOUTH: Ashdown, De Laet, Halford, Mokoena, Hreidarsson, Mullins, Hogg, Nugent, Ward (Cotterill 82), Dickinson (Lawrence 68), Kanu (Webber 84).
NORWICH: Ruddy, Russell Martin, Whitbread, Ward, Tierney, Fox (Lansbury 78), Crofts, Hoolahan, Surman (Lappin 87), Holt, Jackson.
Ref: Andy D’Urso (Essex).