Rampant Ipswich ensured the race for automatic promotion from the Coca-Cola Championship will go down to the wire while leaving Crewe on the verge of relegation.
Goals from Shefki Kuqi, Jim Magilton, Pablo Counago and two from Tommy Miller set up a thrilling final day with Town and Wigan battling it out for second place behind champions Sunderland.
And there could be two divisions between Ipswich and Crewe come August, with ragged Alex slipping into the bottom three at just the wrong time.
Joe Royle's men kicked off knowing a win would take them level on points with Wigan - albeit with a vastly inferior goal difference.
They started with a spring in their step following news of the Latics' draw with Preston earlier in the day and took the lead with just five minutes on the clock.
Ian Westlake threaded the ball between two defenders and Kuqi needed just one touch to steer the ball past the advancing Clayton Ince.
And the home fans were in dreamland when Ipswich went 2-0 up after 12 minutes.
Veteran midfielder Magilton gathered a pass from Westlake and steadied himself on the edge of the box before firing an unstoppable right-foot shot past Ince.
The lively Darren Bent saw an effort drift wide before testing Ince with another shot from just inside the area, while Kuqi and Bent both headed wide from corners as Town looked for a killer third.
Shortly after the break, Bent was denied by Ince and dragged the rebound wide before Miller fired the hosts further ahead.
The former Hartlepool man picked up the ball on the halfway line, ran unchallenged into the Crewe penalty area and neatly curled the ball past the helpless Ince.
Miller doubled his tally after substitute Counago played him in for a simple finish, and Counago got in on the act a minute later when he swept home Bent's cross.
Crewe, for their part, looked every bit a team without a win since New Year's Day, despite David Vaughan's stunning 25-yard consolation strike in the final minute.
And following Brighton's win at Rotherham, their fans know that even victory over Coventry next Sunday may not be enough to save them from the drop into League One.
But Ipswich face the Seagulls on the final day knowing they need to better Wigan's result, and could yet do Crewe a huge favour in the process.
Teams
Ipswich Davis, Wilnis, De Vos, Naylor (Diallo 55), Unsworth,
Miller, Magilton, Westlake, Currie, Bent (Scowcroft 83),
Kuqi (Counago 73).
Subs Not Used: Price, Horlock.
Goals: Kuqi 6, Magilton 12, Miller 51, 81, Counago 82.
Crewe Ince, Moss, Walker, Billy Jones (Bignot 80), Moses,
Bell (Higdon 69), Lunt, Sorvel (Cochrane 55), Vaughan, Varney,
Rivers.
Subs Not Used: Williams, Gary Roberts.
Booked: Cochrane.
Goals: Vaughan 90.
Att: 28,244
Ref: I Williamson (Berkshire).