The game was marred in the 52nd minute when Scunthorpe midfielder Richard Kell was stretchered off with broken left leg which resulted in a second yellow card and a dismissal for Rovers' Craig Disley.
The real honours went to Scunthorpe's two front men, Steve Torpey and Paul Hayes, who have endured a long, barren spell.
Both looked sharp and incisive against a lethargic Rovers' rearguard who were carved open time and time again.
Rarely were the Pirates able to breach the home defence, only ex-Iron man Jamie Forrester and Ryan Williams offered any threat and that was minimal.
Scunthorpe made a lively start and defender Cliff Byrne saw two early efforts fly over the bar before Torpey forced Ryan Clarke into turning away a testing 25-yard shot.
The Pirates were being carved open and Torpey, without a goal in the previous 18 games, broke his duck in the eighth minute when he got in a glancing header from Kell's cross which John Anderson failed to stop.
Kell then tried a raking shot which Clarke again turned around the post.
The onslaught continued and it was Byrne who cut open the Rovers defence on the right before crossing and Torpey out-jumped the defence to grab his second after 14 minutes.
Rovers' response was weak with Forrester and Williams making token shots but never troubling Paul Musselwhite.
Young defender Andy Butler flashed a header wide as Scunthorpe remained in control and from a Peter Beagrie cross, Torpey got a foot to the ball inside the six-yard box but Clarke saved on the line.
The game was virtually over in the 46th minute as Rovers lost possession in midfield and Hayes was able to collect and expertly lob over Clarke for his 20th goal of the season.
Then came the dismissal of Disley, which put the visitors under further pressure, and they conceded a fourth goal with 20 minutes left when Cleveland Taylor got in a looping header from a Beagrie corner.
Rovers were a spent force at this stage and just as Byrne featured in the opening exchanges, he was only inches wide as the game reached a conclusion.