A victory was desperately needed at the end of a trying February, during which the Millers had failed to claim a single win.
Joe Rafferty struck after seven minutes to give Matt Hamshaw’s men the lead and Plymouth were unable to produce a response.
It was not a case of the hosts clinging on for dear life either, as the Millers continued to probe in search of a two-goal cushion.
A second goal may have eluded them, but there were jubilant scenes at the full-time whistle when victory was secured.
Here are The Yorkshire Post’s ratings from the New York Stadium.
9. Ar'jany Martha - 6
A workmanlike display on the right flank, where he struggled to conjure up much magic. | Jonathan Gawthorpe
10. Harry Gray - 8
Looked dangerous every time he got on the ball down the left flank. It is hardly a secret Leeds United have a player on their hands. | Jonathan Gawthorpe
11. Duncan Watmore - 8
He has spent the bulk of his career at a higher level than League One and it showed. Sharp as a knife on the ball and intelligent with his movement before being withdrawn early in the second half. Perhaps needs his minutes managing having seen such little action this season. | George Wood/Getty Images
12. Sam Nombe - 7
Did not have his finishing boots on but was a persistent menace. | Jonathan Gawthorpe