Ipswich secured an immediate return to the Premier League with victory over QPR on the final day of the Championship season.
It meant Millwall and Middlesbrough had to settle for a play-off spot, and are joined by Southampton and Hull.
The Tractor Boys came racing out of the traps and effectively put the game - and day - to bed inside 10 minutes.
George Hirst bundled home the opener after just three minutes, and then set Jaden Philogene for a second in the ninth minute.
The result means Kieran McKenna is the first Town manager to mastermind three promotions – two to the top flight.
News travelled quickly to Millwall and those Middlesbrough fans in Wrexham, with their hopes of second spot being all but extinguished so early on.
Femi Azeez scored both goals as Millwall had to settle for a place in play-offs despite finishing the regular season with a comfortable 2-0 victory over relegated Oxford.
Reaching the second-tier play-offs for the first time since 2002 represents a significant achievement for Millwall, who will face Hull in the semi-finals after they snatched sixth place on the final day.
It meant attentions turned to the play-off race, and who out of Hull, Wrexham and Derby would join Southampton and that disappointed duo.
Wrexham’s hopes of a historic fourth consecutive promotion were ended with a 2- Championship draw against Middlesbrough at the SToK Cae Ras.
Hull took advantage of Wrexham – who were playing National League football three years ago – dropping points to secure sixth spot with a 2-1 win over Norwich.
A brace from Oli McBurnie saw the Tigers seize their moment to regain a top-six finish – a position in which they have occupied for most of the season – after they came from behind at the MKM Stadium.
Sheffield United staged a second half comeback to win 2-1 at Pride Park and end Derby’s Championship play-off hopes.
Derby were in control at the break through Sam Szmodics early goal but the visitors came back strongly to dash the home side’s dream of a top-six finish.
Additional reporting by Press Association.
