Rotherham kick-started their bid to catch up in League One by inflicting Blackpool's third straight defeat.
The visitors, docked 10 points for financial shortcomings, grabbed the winner deep in the second half.
Substitute Will Hoskins fired home from close range after a flick-on from fellow striker Delroy Facey.
Rotherham goalkeeper Neil Cutler twice denied on-loan Middlesbrough striker Danny Graham before Hoskins' decisive intervention on 78 minutes.
Blackpool: Evans, Coid, Jackson, Barker, Tierney (Evatt 81), Forbes, Southern, Gillett, Prendergast (Parker 57), Vernon (Hoolahan 57), Graham.
Subs Not Used: Clancy, Fox.
Rotherham: Cutler, Worrell, Mills, Sharps, Robertson, Partridge (Wiseman 63), Williamson, Bopp, Keane, Hibbert (Hoskins 67), Facey.
Subs Not Used: Montgomery, Woods, Hurst.
Goals: Hoskins 78.
Ref: K Friend (Leicestershire).