Doncaster earned consecutive Sky Bet League One wins for the first time this season as they comfortably saw off struggling Northampton at the Keepmoat.Veteran midfielder James Coppinger marked his return from injury with a goal before Niall Mason scored his second penalty in as many games to give Rovers a cushion at half time. Andy Butler made sure of the three points just after the hour mark.Butler, Ben Whiteman and Tommy Rowe all went close to giving Doncaster the lead before Coppinger did, bundling in from close range in the 33rd minute after John Marquis and Alfie May both had efforts saved.Northampton were rather toothless throughout but Shaun McWilliams drew a fine low save from Ian Lawlor.Moments later, Matt Grimes clipped Marquis from behind in the box and Mason drilled home the penalty to make it 2-0 on 43 minutes.Doncaster were comfortable after the break with Northampton struggling to threaten.And they put the game to bed in the 66th minute when Butler forced the ball home after a Mathieu Baudry header was cleared off the line.