Sunderland won promotion to the Premiership after they beat Leicester at The Stadium of Light.
Stewart celebrates scoring for newly-promoted Sunderland
Mick McCarthy's side came from a goal down after Alan Maybury put the Foxes ahead after five minutes.
Marcus Stewart and Steven Caldwell scored the crucial goals to clinch the Black Cats' return to the top flight.
Ipswich's failure to win at Leeds means they cannot catch Sunderland, with the news sparking wild scenes of celebration among the home fans.
It was an enthralling contest from the start with Stewart passing up the chance to put Sunderland ahead with just 57 seconds on the clock, firing a close-range effort just wide.
Leicester spent the early exchanges camped in their own half but took the lead with their first attack.
From inside his own half, Foxes skipper Danny Tiatto guided a pass through to left-back Maybury, who held off Stephen Wright and tucked the ball inside debutant goalkeeper Ben Alnwick's far post.
The visitors were looking to extend their lead and 18-year-old Alnwick had to show his potential with two fine saves to keep out David Connolly's effort and a Mark de Vries strike.
The action continued at break-neck speed, with a Stewart cross rolling across the six-yard box, Lawrence rifling a shot just wide and even Wright testing Foxes goalkeeper Ian Walker.
In the 23rd minute, the Black Cats were level. Wright knocked the ball up to Chris Brown, who guided the ball inside the full-back for Stewart to fire past Walker for his 17th of the campaign.
The start of the second half was not quite as energetic but that changed when Walker showed good reflexes to get a hand to Brown's header from Dean Whitehead's cross.
The home side's frustrations boiled over when Dion Dublin fouled Brown in front of the managers' dug-outs.
Brown was furious and after going head-to-head with Dublin, had to be dragged away by his manager before both players were booked.
But Sunderland's patience finally paid off just before the hour, when Lawrence's corner was headed in by Black Cats defender Caldwell to spark raucous celebrations.
Sunderland's return to the Premiership ends a two-year exile from the division.
Leicester manager Craig Levein:
"It gets monotonous doesn't it? We played well but we didn't get any points. That has been the story of the season.
"How many times have I said after games that we played well? But you gt fed up saying the same things. We had chances to go two or three goals up.
"But good luck to Sunderland. They have been very consistent."
Sunderland: Alnwick, Wright, Breen, Caldwell, Arca, Lawrence, Whitehead, Robinson, Welsh (Danny Collins 71), Stewart (Elliott 81), Brown (Deane 77).
Subs Not Used: Ingham, Thornton.
Booked: Wright, Robinson, Brown.
Goals: Stewart 23, Caldwell 60.
Leicester: Walker, Kenton, McCarthy, Dublin, Maybury, Hughes, Gudjonsson (Williams 66), Nalis (Stearman 68), Tiatto, Connolly, de Vries (Moore 25).
Subs Not Used: Gillespie, Hirschfeld.
Booked: Gudjonsson, Dublin, Stearman.
Goals: Maybury 5.
Ref: M Jones (Cheshire).