Nottingham Forest moved seven points clear of the Championship relegation zone thanks to Dexter Blackstock's first-half winner against Peterborough.
Forest made all of the the early running with Garath McCleary, Andy Reid and Lewis McGugan having chances.
McGugan also hit the post with an 18-yard shot before Blackstock curled in a fine strike from McCleary's cross.
Posh barely threatened and Forest held on despite winger McCleary being sent off for a foul on Grant McCann.
The visitors were the better side throughout and Peterborough were unable to take advantage of McCleary's straight red card on 78 minutes.
George Boyd did have a good chance to snatch a point for mid-table Peterborough late on, but mis-hit his shot from inside the area.
However, that would have been tough on a Reds side who created the majority of chances.
Peterborough's Paul Jones was by far the busier of the two keepers and did well to tip Blackstock's header over the bar early on and also made a decent parrying save to deny Radoslaw Majewski.
Adlene Guedioura and McGugan then threatened with long-range efforts, and although Boyd and Joe Newell fired shots over at the other end, the away side's dominance continued.
Blackstock made the breakthrough seven minutes before half-time, he skilfully controlled McCleary's cross from the right and lashed the ball into the net via the underside of the bar.
Gaby Zakuani headed over for Posh while Blackstock would have had a second goal had it not been blocked by Jones.
Majewski and Blackstock could have increased the lead after the interval and, although going down to 10 men disrupted them, Forest secured the win with relative ease.
Nottingham Forest manager Steve Cotterill: "We could have been home and dry by half-time but you always fear you may get hit by a sucker-punch at 1-0.
"Thankfully that didn't happen and we did well to keep our concentration after going down to 10 men to get a good result.
"I will be amazed if the red card is not rescinded, though. I thought the referee Carl Boyeson was hasty when making the decision and I gather he feels he may have made a mistake.
"I take my hat off to Carl Boyeson if that is the case so hopefully the decision will be looked at, although I may not have been so charming if we had lost 2-1."
Peterborough manager Darren Ferguson: "We're nine points clear of the bottom three with four games to go, so we'll be fine.
"I have to admit we were disappointing today, though. It was just a case of being one game too many for our small squad and we had very little left in the tank.
"We tried all sorts of different systems and permutations, but it was one of those days where nothing came off."