F-T: Fourth place for Millers and it's Scunthorpe in the play-offs ... Rotherham United 1 Blackpool 0
Will Vaulks fired the Millers in front in the sun at AESSEAL New York Stadium and there was a party atmosphere after his 58th-minute strike as supporters celebrated a triumphant end to the regular campaign.
Paul Warne's side will now be away to Scunthorpe next Saturday, with the semi-final second leg at New York the following Wednesday.
Rotherham performed a lap of appreciation after the final whistle.The contest had been far from a classic but the players deserved their ovation after a memorable season which has brought 24 wins following last year's drop from the Championship.
Vaulks drove his left-footed effort home from just inside the penalty area to put the Millers into a deserved lead and both sides had chances to score after that as the game opened up.
Nathan Delfouneso missed a sitter for the visitors after 74 minutes, Christoffer Mafoumbi pulled off a stunning stop to deny Vaulks a second five minutes later, substitute Caolan Lavery was just wide for the home side and then Mark Rodak produced an 81st-minute save even better than Mafoumbi's to claw away Kelvin Mellor's header.
Dan Agyei and Ollie Turton were close to equalisers in time added on.
Rotherham did most of the attacking in the first half and had several sights of goal without really troubling Mafoumbi.
Michael Smith shot across goal and wide early on to set the tone for an opening period of Millers' attempts that missed the target.
Joe Mattock looped a free header from Vaulks' corner over the bar before Ryan Williams shot wildly and wastefully towards the corner flag when he could have cut the ball back.
Richard Wood stabbed a close-range effort wide, a Jon Taylor cross just evaded David Ball, Smith's shot failed to match the quality of his first touch when he was played in by Josh Emmanuel and Vaulks put a 20-yard shot into the advertising hoardings.
This match will quickly be forgotten. The Millers' season won't be.
Rotherham (4-4-2): Rodak; Emmanuel, Ihiekwe, Wood, Mattock; Taylor, Palmer, Vaulks, Williams (Forde 71); Ball (Towell 76), Smith (Lavery 55). Subs not used: Price, Ajayi, Purrington, Yates.
Blackpool (4-4-2): Mafoumbi; Turton, Tilt, Robertson, Daniel; Mellor, Ryan (Cooke H-T), Spearing, Soloman-Otabor (Agyei 67); Longstaff (Cullen 67), Delfouneso. Subs not used: Williams, Clayton, Anderton, Menga.
Goals: Vaulks 58 (Rotherham).
Referee: Ross Joyce (Cleveland).
Attendance: 9,512 (682).