Rotherham ensured they will be playing Championship football again next season with a battling 1-0 win over 10-man Middlesbrough.
The Millers had been relegated in each of their previous three campaigns at this level, but Hakeem Odoffin's powerful second-half strike secured survival ahead of what would have been a nervy final-day trip to bottom side Wigan.
Victory guarantees they cannot be caught by Reading who, following their six-point deduction, occupy the third and final relegation spot. The Royals can now only catch Huddersfield, who are three points above them, have a game in hand and a slightly better goal difference.
Middlesbrough, who have already secured a play-off berth but could have replaced Luton in third, lost defender Anfernee Dijksteel to a straight red card just before half-time and could find no way back once Odoffin struck three minutes into the second half.
It might have been a different story had the visitors made the most of an early chance when Riley McGree outpaced Richard Wood. The Boro forward flicked his effort beyond home goalkeeper Viktor Johansson, but Wood managed to stop the ball from crossing the line.
Rotherham then forged a chance of their own from Wes Harding's long throw, but Jamie Lindsay fired off target.
The home side suffered a blow when dangerman Chiedozie Ogbene picked up an injury and had to be replaced, but the Millers still managed a period on top without the Republic of Ireland international, with Middlesbrough-born Jordan Hugill almost getting on the end of a curling cross from Ollie Rathbone.
It was Middlesbrough's turn to suffer a setback just before the break when they were reduced to 10 men after Dijksteel bundled over Hugill and blocked his path to goal.
It gave Rotherham a shooting chance from the edge of the box, but Cohen Bramall's free-kick was off target.
United did not have to wait too much longer to take the lead, though, with Odoffin netting what would prove to be the winner in the 48th minute when he powered a low shot from the edge of the box past Zach Steffen.
However, even with a man down, Middlesbrough continued to pose a threat.
Former Rotherham midfielder Dan Barlaser, who swapped clubs in January, tried to get his new team back on level terms, but his effort from distance was comfortably over the bar.
There was an even bigger scare for the home side when a flicked ball from McGree bounced kindly to half-time substitute Tommy Smith, who sliced over at the back post.
Rotherham fans were calling for another red card when Paddy McNair looked like he had hauled down Georgie Kelly on his way through to goal, but the appeals were dismissed by referee Keith Stroud.
Championship top scorer Chuba Akpom had been having a quiet afternoon until he burst into life with a menacing run and strike which had to be deflected over the bar.
Johansson also had to pull off a despairing late save when a cross was diverted goalwards by Lindsay as Rotherham held on for a vital victory.