The Pilgrims were always in command of the match and an avalanche of goals looked on the cards when striker Sylvan Ebanks-Blake fired home in the 15th minute.
The former Manchester United man picked up the rebound after Rovers' Scottish international keeper Neil Sullivan spilled David Norris' shot.
It was Ebanks-Blake's seventh goal in his last ten games, even though he has yet to start a Championship match this term.
The Pilgrims peppered the visitors' goal for the remainder of the game but could not break through some desperate defending until second-half stoppage time.
It took a piece of individual skill from young midfielder Luke Summerfield to give the scoreline a more realistic look.
Substitute Summerfield stepped up to take a 35-yard free-kick and duly dispatched the ball past Sullivan to relieve the nerves of the home side's fans.
Argyle started at breakneck pace and Ebanks-Blake's early header from Paul Connolly's right-wing cross nearly broke the early deadlock.
Norris had a shot saved by Sullivan, and Hungarian international Akos Buzsaky fired a free-kick over before the Pilgrims were denied a second only a linesman's flag for offside against Nick Chadwick.
Buzsaky's countryman, Krisztian Timar swung right boot only for Sullivan to kick the ball away early in the second half and Buzsaky shot wide from two yards after a mazy run.
Peter Halmosi's shot was blocked by half-time Doncaster substitute Gordon Greer, before he shot over as well.
Visiting midfielder Martin Woods then sliced Summerfield's right-wing corner back towards his own goal and only just over the crossbar.
However, it was Summerfield who rounded off the evening with his tremendous long-range strike.