The Yorkshire outfit have now gone eight games without a win after goals from Pelly-Ruddock Mpanzu, Kazenga LuaLua, Luke Berry and Danny Hylton sealed a thoroughly deserved victory for the Hatters.
Barnsley’s dramatic last gasp victory at Walsall earlier in the day had put the pressure on Luton by cutting the gap at the top to two points.
But Mick Harford’s men rose to the challenge against a hugely disappointing Rovers side who were second best for long periods and could easily have lost by a bigger margin with the hosts hitting the crossbar twice through Elliot Lee.
Peterborough United’s win at home to Southend means Doncaster slip to seventh. Tuesday’s game at home to Bristol Rovers has now taken on huge proportions for McCann’s men.
Pelly-Ruddock Mpanzu opened the scoring on 34 minutes, the midfielder collecting a lay-off by Kazenga LuaLua before stroking a shot from 20 yards beyond Marko Marosi.
The goal had been coming, Luton having gradually exerted more and more control after what had been an error-prone first quarter from both teams.
Rovers struggled in midfield, Elliot Lee afforded far too much space on the ball and almost able to pick his passes unchallenged.
Grant McCann’s side were fortunate to reach the break just a goal down with Marosi having to get down smartly to save from LuaLua.
Danny Hylton was also agonisingly close to converting a cross from Andrew Shinnie that flashed across goal.
John Marquis had cut an isolated figure in those opening 45 minutes. But he still had a decent chance, controlling a right wing cross on his shot before hitting a shot that James Shea saved easily.
The hope for the 544 travelling fans was that manager McCann could inspire a big improvement after the break.
Luton, however, doubled their advantage 12 minutes after the restart to effectively kill off the Yorkshire club’s chances of rescuing anything from the trip down the M1.
Lovely wingplay from Jack Stacey saw the Hatters man evaded three challenges before crossing for Danny Hylton to score.
After that, it was one way traffic as Lee hit the crossbar and then Hylton had a second goal ruled out for offside.
Lee then brought a flying save from Marosi that saw the ball strike the top of the crossbar before the Rovers keeper had to get down smartly to deny Hylton.
There was nothing, though, Marosi could do eight minutes from time when Lua-Lua was played through and lifted a shot over the keeper.
More pain lay ahead for Doncaster, Luke Berry netting in stoppage time with the home side’s 29th effort on goal of the afternoon. Rovers, in contrast, managed just four to underline the gulf between the two teams.