Chris Wilder's side scored in either half, John-Joe O'Toole and Marc Richards getting the goals that mean Town are five points clear at the top of the League Two table and fourteen points above Bristol Rovers in fourth.
Two weeks without a match did not affect the Cobblers, who included new signings Prosser and Rose on the substitute's bench.
5,342 watched the action with Northampton now having a week to prepare for two important away games in the space of four days against teams currently in the top six, Leyton Orient and Oxford United.