COURTNEY Cameron scored a late goal to give the Millers victory on the road at Rochdale.
Kayode Odejayi had equalised for Rotherham on 78 minutes after Ashley Grimes had given the hosts a first half lead.
Manager Steve Evans had made two changes to the team that beat Accrington Stanley 4-1 at the New York Stadium on Saturday. Ben Pringle returned in place of Cameron and Odejayi was up front instead of Alex Revell.
Grimes’ goal came after good play from Joe Rafferty and the in-form striker fired into the top left hand corner of Andy Warrington’s goal.
With Rotherham struggling to threaten in the first half Evans was quick to make changes in the second.
Kieran Agard was brought off for Cameron after 57 minutes. And with 22 minutes to play Revell came on for Pringle.
But the Millers couldn’t fashion any clear cup opportunities with corners by Cameron and Michael O’Connor being their biggest threat.
However, Odejayi was able to get on the end of a Cameron cross to make it 1-1 after 78 minutes.
The match appeared to be heading for a draw until Cameron pounced in the 90th minute.
ROCHDALE: Lillis, Rafferty, R Edwards, P Edwards, McIntyre, Tutte, Cavanagh, Kennedy, Grant, Grimes, Gornell. Subs: Bennett, Barry-Murphy, Donnelly, Putterill, Adebola, Craney, Smith.
ROTHERHAM UNITED: Warrington, Bradley, Mullins, Arnason, Ridehalgh, Taylor, O’Connor, Pringle, Frecklington, Agard, Odejayi. Subs: Sharps, O’Connell, Cameron, Walker, Revell, Thompson.
Referee: Stuart Attwell (Warwicks).
See The Star tomorrow for full report, reaction and more.