Peterborough maintained their play-off push with a fourth successive victory and dented Doncaster's hopes in the process with a 2-0 win.Goals in each half from Luke James and Conor Washington gave Peterborough a deserved victory and Rovers could have no complaints about the result.Peterborough looked sharper from the start and worked their socks off to prevent the home side settling into their stride.James put them in front in the 16th minute with a diving header from Jon Taylor's right-wing cross after Doncaster had given the ball away.Rovers had enough chances to hit back, but Harry Forrester and Curtis Main had shots saved in quick succession before Forrester was out of luck again when he had another effort headed off the goalline by Michael Smith.The home side failed to lift their game after the interval as Peterborough defended their lead with some resolute work at the back.Washington wrapped it up for the visitors following a breakaway in the 88th minute when he slotted the ball home from Kyle Vassell's cross.