Like their season as a whole, they made hard work of it in the end, but there is no doubting they deserve their promotion, secured with a hard-fought 2-0 win at Gillingham.
Sadly, some of the credit the players did their club was undone by morons who ran on the field at full-time not to celebrate but throw punches, bottles and even a plastic steward's seat.
Chiedozie Ogbene did his best to disperse the mindless minority but it was an unwanted distraction from a gutsy performance by a team who have shown consistency this season to wrap up second place in League One.
The goals that inked it in came from unlikely sources in centre-back Rarmani Edmonds-Green and Georgie Kelly, off the bench for his Football League debut.
There were some nervous moments inbetween but this has perhaps been the toughest League One ever, so it should come as no surprise.
There are some big-budget still sweating on promotion and plenty more who have missed the boat.
The first half was a game of defence versus attack and it needed two defenders to make the breakthrough.
Relegation-threatened Gillingham packed men behind the ball but Rotherham were able to get the ball wide and into the box, whether through crosses in open play, dead balls or long throw-ins.
At times you worried they were getting too lured into the direct football that is Gillingham's strength.
It was their outside centre-backs who carried the most threat, Michael Ihiekwe and Huddersfield Town loanee Edmonds-Green taking advantage of Gillingham's lack of ambition to pile forward whenever possible.
Ihiekwe headed a Wes Harding ball over and one from Ollie Rathbone wide.
Edmonds-Green forced an outstanding reaction save from Aaron Chapman having earlier burst from the back adn exchanged a one-two with Rathbone, only for Jordi Osei-Tutu's cross to be cut out when he was played in.
All Gillingham had to offer in response at that stage was a curling free-kick from Ben Reeves which Viktor Johansson caught comfortably.
Ben Wiles also got forward but put a Michael Smith cross wide.
Rotherham had the backing of a packed away end which was already pumped up before Paul Warne left the tunnel early to go and applaud them.
Eventually, the pressure told, and it was no surprise Ihiekwe and Edmonds-Green were involved, the former hanging in the air at Dan Barlaser's corner, and the latter applying the final tough after 35 minutes.
"We are top of the league," chanted the Rotherham fans before Wigan Athletic took the lead at Shrewsbury Town to change that.
Maybe the roof might have come in on Gillingham had Smith not steered a very presentable chance from Chiedozie Ogbene's square pass wide.
Instead the half finished with a real warning shot, Ben Thompson volleying against the underside of the crossbar at a corner. The job was far from done.
Gillingham came on strong at the start of the second half, encouraged by a crowd who were perhaps themselves encourgaed that the team they needed to outdo, Fleetwood Town, were losing.
The MIllers were forced to endure a real bombardment but stood firm, Richard Wood winning his headers and Barlaser produced a crucial interception to stop Thompson picking out Ollie Lee. Edmonds-Green needed an excellent bit of defending to stop a long throw doing damage.
Max Ehmer touched an excellent curling free-kick from Reeves wide after Wood had put himself in the referee's notebook.
Joe Mattock came on. For one of the first times this season Rotherham had two full-backs rather than wingers at wing-back.
But the storm was weathered.
Chapman saved when Wiles got across his man onto an Ogbene cross and Osei-Tutu's follow-up deflected wide. It was the first of a hat-trick of saves from the midfielder. Ihiekwe headed a corner straight at the goalkeeper.
Wood's disallowed goal prompted a pitch invasion and when Georgie Kelly, making his Football League debut from the bench, thumped in Ogbene's pull-back after 89 minutes there was pandemonium, flares and fans everywhere.
Once the stewards got them off the pitch they were lined up behind the byline waiting to burst back on as soon as the eight added minutes were up and duly did.
With Gillingham relegated and their fans demanding the resignation of long-serving chairman Paul Scally, the full-time scenes were uglier than Warne and his players deserved.
It was by no means the first example of crowd trouble at Rotherham this season, unfortunately.
The players, though, have been magnificent - nothing should distract from that.
Gillingham: Chapman; Jackson, Masterson (Phillips 74), Ehmer, Tucker, Tutonda (Sithole 87); O'Keefe, Lee (Carayol 67), Thompson; Reeves; Oliver.
Unused substitutes: Dahlberg, Lintott, Maghoma, Chambers.
Rotherham United: Johansson; Edmonds-Green, Wood, Ihiekwe; Harding, Rathbone (Odoffin 90), Barlaser, Osei-Tutu (Mattock 67); Wiles, Ogbene; Smith (Kelly 80).
Unused substitutes: Chapman, Bola, Lindsay, Kayode.
Referee: S Barrott (West Yorkshire).