The Millers dominated from start to finish against an opposition who had been shellshocked by the midweek loss of manager Micky Adams.
Having had a goal ruled out for offside after only three minutes Rotherham followed that up with one that did count after ten minutes.
A long clearance out of defence was headed on by Ryan Taylor, and Will Atkinson touched the ball to the advancing Nicky Law who slammed a first time shot past Stuart Tomlinson.
And nine minutes later the home side doubled their lead with a copy book goal when they cleverly switched play from the left to the right for Danny Coid to cross and pick out Ryan Taylor whose powerful header flew over Tomlinson and into the back of the net.
After 31 minutes Andy Warrington made a smart save to deny Justin Richards, but two minutes later, Vale were reduced to ten men when goalkeeper Tomlinson came racing out of his area and bowled over Marcus Marshall with his challenge.
Clearly the last defender, Tomlinson was immediately shown the red card by referee Graham Salisbury and Vale were forced to sacrifice striker Justin Richards to bring on substitute goalkeeper Chris Martin.
And 38 seconds into the second half, Rotherham made it three when Will Atkinson went on a diagonal run across the Vale penalty and flicked a shot past everyone and into the net.
The fourth goal came after 69 minutes, a spectacular overhead effort from Ryan Taylor from Le Fondre's cross.
And Rotherham made it five six minutes from time when Arsenal loanee Mark Randall crashed in a magnificent 25-yard angled shot from Johnny Mullins throw in.