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.
1. Rotherham United player ratings
The player ratings are in following Rotherham United's meeting with Plymouth Argyle. | Harriet Massey/Getty Images
2. Ted Cann - 7
Solid when called upon, even if his distribution required some work. | Jonathan Gawthorpe
3. Joe Rafferty - 7
Won his battles at the back and opened the scoring with a deft flick. | Pete Norton/Getty Images
4. Jamal Baptiste - 7
Caught ball-watching on a few occasions but enjoyed success in duels when it mattered. | Jonathan Gawthorpe