George Boyd scored the only goal of the game as Peterborough beat Nottingham Forest for the first time ever in league competition.
Midfielder Daniel Kearns found the former Forest forward inside the opening 20 minutes, allowing Boyd to curl his shot beyond keeper Lee Camp and into the top corner from outside the area.
Forest's Lewis McGugan went closest for the home side when striker Dexter Blackstock put him through on Posh keeper Joe Lewis, but the midfielder lifted his attempt over the bar and allowed the visitors to escape with a win.
