KNIGHTS’ forwards drove Doncaster to a fourth straight league win at a rain-drenched Castle Park.
A James Love penalty for Plymouth was the only score during a forgettable first half which saw both teams cancel each other out.
But Doncaster, as has been their way this season, got stronger as the game went on and second half tries from Andy Boyde and David McIlwaine cemented fourth spot in the Championship.
Boyde was driven over the line on 51 minutes by the home side’s dominant forward line.
And full back McIlwaine, a stand-out performer during the first month of the campaign, then burst through the Plymouth defence on the hour mark to make sure of victory, Mick Whitehead adding the conversion.
Knights host local rivals Leeds Carnegie on Wednesday night in the British & Irish Cup (7.30pm).