Millwall eased their relegation fears and kept Doncaster one place off the foot of the Championship table after a comprehensive win at the Keepmoat.
James Henry crossed from the right for the unmarked Andy Keogh to head the Lions in front from six yards.
On-loan Tottenham striker Harry Kane added a speculative long-range strike that eluded the grasp of Carl Ikeme.
Henry superbly found Darius Henderson, who finished in style to put Millwall nine points clear of the drop zone.
Doncaster manager Dean Saunders was subjected to criticism from sections of the home support after a mediocre display by his team.
Millwall took the lead with their first meaningful attack in the eighth minute.
Henry was allowed to progress unchallenged down the right and his excellent cross picked out former Wolves striker Keogh, who made no mistake.
Matters went from bad to worse for Rovers as Ikeme failed to keep out Kane's well-struck shot, and with the visitors continuing to cut through the home defence with ease, the Spurs man volleyed narrowly wide soon afterwards.
The main attacking threat from the home side came from an unlikely source, full-back Tommy Spurr, who twice cut in from the left but missed the target on both occasions.
A fierce strike from Henry was kept out by a combination of the woodwork and Ikeme, who then produced a superb one-handed save to thwart Henderson.
Millwall's top scorer soon got on the scoresheet, however, with a deft finish at the near post.
Frederic Piquionne went close for Rovers soon after, but Lions goalkeeper Maik Taylor was not called into action until the 79th minute, and even then a tame Giles Barnes header merely prompted ironic cheers from the beleaguered home contingent.
Millwall manager Kenny Jackett said: "It was a vital game tonight against one of our competitors at the bottom, to not let them come back at us. We've very pleased with the result, first and foremost, and the performance was good. Defensively we were solid and going forward we worked their keeper well and created a number of chances.
"Portsmouth had a good win, and obviously Forest (who won 7-3 at Leeds), and Coventry play on Wednesday so it was vital that we did win because people can come back at you."
Doncaster boss Dean Saunders added: "Football is not easy. We've got to roll our sleeves up, come out fighting, have some belief in ourselves and have some nerve. We're all good players when we're 2-0 up. Who wants the ball when you're 2-0 down and the crowd are ready to have a go at you? I'll keep fighting and I'll make sure the players keep fighting.
"If I was a Doncaster fan I would be devastated right now, but all is not lost. When they get up in the morning and have a look at the league table they will see that we can still do it."