After being one down at the break, a three goal spell in ten minutes from leaders Rochdale put paid to Rotherham's hopes of a win which would have taken them back into the top three.
Ronnie Moore put out an unchanged side from the 11 that had won three days earlier at Burton Albion, with leading scorer Adam Le Fondre deemed fit after an injury scare looked like he might miss the game against his former club.
The first chance of the game fell to Kevin Ellison, with him shooting just wide of Fiedling's left hand post.
With the Millers passing the ball round well, the important first goal was not long in coming, however it was Rochdale that scored in the 9th minute when former Miller Chris O'Grady broke clear on the right and after a cruel deflection on his cross, Chris Dagnall swept home.
The goal struck the Millers into action with Josh Walker twice being denied with shots by Fielding.
Tom Pope then went close with a header, with Fielding again saving from Ellison.
The Millers lost Ian Sharps on 23 minutes, limping off injured as Gavin Gunning moving to centre back with Jamie Green coming on to slot into the left-back position.
With the new back four trying to settle, Rochdale had a chance to double their lead just before the break when a whipped free kick was tipped over the bar by Andy Warrington.
The Second-half started well for the Millers, when Danny Harrison had a shot saved at the expense of a corner. The corner led to Le Fondre having a header cleared off the goal line.
But as the second half rolled on Rochdale were getting the upper-hand in midfield, and in the 64th minute scored what turned out to be a unfortunate goal for the Millers to concede.
A cross from O'Grady into the box was sliced by Gunning onto Green's body and into the net to put Dale two goals up.
Dale's tails were up and on 71 minutes the third goal came when Craig Dawson rose higher than the rest to score his 11th goal of the season from a left wing corner.
O'Grady had been a thorn in the Millers side all evening and he was rewarded scoring Rochdales fourth and his 19th of the season. With the Millers pushing to try and rescue something from the game, a long ball over the defence found him onside and he raced away to slot past Warrington.
It was Warrington who prevented the scoreline looking even more depressing for the good sized contingent of traveling fans, including a fine double save in the closing minutes.