Last-gasp misery for Millers but still another point on the board ... on-the-whistle report: Luton Town 1 Rotherham United 1
They were leading as stoppage time approached but conceded an equaliser in the 89th minute.
A shot that deflected in was a bitter pill to swallow after they had been in front from the first minute at Kenilworth Road following their midweek derby success at Sheffield United.
The Millers go into the month-long World Cup shutdown 16th in the Championship.
They got off to a flying start and were ahead after only 55 seconds as Jamie Lindsay took aim and superbly drove the ball into the far corner.
The home side responded with a spell of pressure but had only a glanced header - comfortably gathered by Viktor Johansson - from Millers old boy Carlton Morris to show for their efforts in the opening quarter of an hour.
Tom Lockyer headed a corner wide as Luton continued to probe and Morris spurned a glorious chance to equalise on 28 minutes.
The Hatters robbed Dan Barlaser of possession and broke quickly but the striker could only shoot wide from the edge of the area when Elijah Adebayo's square ball left the goal gaping.
Luton were playing their first match after the departure of long-serving manager Nathan Jones to Premier League Southampton.
However, the home crowd were buoyed by the presence on the touchline of club legend Mick Harford who has agreed to take caretaker charge.
The head of recruitment, who is battling prostate cancer, is a huge figure at Kenilworth Road, having been a Luton striker, coach, boss and director of football in the past.
He received a rapturous ovation when he saluted supporters just before kick-off.
With ten minutes to go to the interval, Johansson had to be at his spectacular best to tip away Allan Campbell's 20-yard effort following another speedy Hatters break.
Rotherham were posing a sporadic attacking threat but the ball wasn't sticking up front and was coming back too often.
Johansson was called into action again as he kept out James Bree's angled drive and the Millers, who had had a lot of defending to do and had done it well, were relieved to go in at half-time still in front.
Unsurprisingly, following Tuesday's memorable triumph at Bramall Lane, they had kept faith with the same 11 players who had started at Bramall Lane.
Striker Conor Washington came back into the squad even though he may require surgery on a troublesome knee.
There were few attempts on goal in the second half until Cohen Bramall stung keeper Ethan Horvath's palms with a 68th-minute free-kick for the Millers.
Alfie Doughty's curling effort brought an excellent stop from Johansson as Luton began to look dangerous again in the closing stages.
The visitors' rearguard remained up to the test until Jordan Clark shot in the dying minutes and the ball went in off Luke Berry.
It was tough to take but a draw was an excellent result.
Luton Town (3-5-2): Ethan Horvath; Gabe Osho (Luke Berry 57), Tom Lockyer, Amari'i Bell; James Bree, Allan Campbell (Luke Freeman 70), Pelly-Ruddock Mpanzu, Jordan Clark, Alfie Doughty; Elijah Adebayo (Harry Cornick 70), Carlton Morris. Subs not used: Harry Isted, Louie Watson, Josh Williams, Casey Petit.
Rotherham (3-5-1-1): Viktor Johansson; Lee Peltier, Cameron Humphreys, Wes Harding; Peter Kioso (Brooke Norton-Cuffy H-T), Jamie Lindsay (Hakeem Odoffin 90+1), Dan Barlaser, Ollie Rathbone, Cohen Bramall; Ben Wiles (Tom Eaves 76); Chiedozie Ogbene (Conor Washington. 90+1). Subs not used: Josh Vickers, Richard Wood, Scott High.
Referee: Stephen Martin (Staffordshire).
Goals: Lindsay 1 (Rotherham); Berry 89 (Luton).
Attendance: 10,071 (1,040).