The home side, who were beaten 3-0 by Queen of the South in midweek, were led by a brace from Nicky Law while Nicky Clarke and Haris Vuckic were also on the scoresheet.
Victory sees the Gers remain joint second with Hibernian while defeat for Rovers leaves them in sixth place.
Rangers made the perfect start when Law’s corner from the right was nodded in by an unmarked Clarke in the sixth minute.
Stuart McCall’s side dominated for the first of the half with Law’s long-range drive saved by Kevin Cuthbert while the same player set up Marius Zaliukas whose header was off target.
They doubled their lead when Vuckic cut inside from the right and fired in a low effort for his seventh goal of the season on 27 minutes.
The visitors’ best chance of the half fell to Ryan Conroy, whose whipped free-kick was parried by Cameron Bell.
But Rangers continued to press, with Andy Murdoch flashing a shot wide from distance, while Zaliukas nodded over again following a corner.
The second half began more evenly and Raith could have pegged a goal back when the hosts failed to clear and Lewis Vaughan’s snapshot flew wide, while at the other end Lee Wallace thumped his effort inches over after cutting inside from the left.
Rangers carved out the better chances for the rest of the half though with Wallace dragging his shot wide from Law’s pass.
And they sealed the ponits on 72 minutes when Law rattled the crossbar with his first effort and tucked in the rebound for his first goal since January.
Rangers could have scored a couple more in the dying minutes with Law’s shot well saved by Cuthbert.
But the keeper could do nothing about the home side’s fourth goal with Law curling his effort into the corner from the edge of the box to cap off an impressive display.