Rookie midfielder Dwayne Mattis fired Huddersfield to their first win of the season with a wonder goal.
The Terriers had stumbled in the first two games of the season with defeats against Brentford and newcomers Plymouth Argyle, but condemned Posh to their second home defeat in four days with a clinical display.
And Town boss Mick Wadsworth reckoned Mattis' 10th minute beauty was worthy of winning any game.
He said: "I've told the midfielders not to be frightened to have a go at goal, and look what Dwayne did. It was a real class goal and the win was very important for us."
The wonder strike arrived after neat build-up play down the left-hand side from Chris Holland who enticed Mattis to have a crack from distance and the Ireland youth international let fly with a thunderous effort that bulged the top corner of the net.
Mattis' game came to an end at half time as he was substituted with heat exhaustion, paving the way for Town defenders Adie Moses and Eddie Youds to take centre stage.
The strong duo, who both possess Premiership experience, were rock solid for the entire 90 minutes, much to the frustration of Peterborough's front pairing of veteran Andy Clarke and rookie Francis Green.
The home side were reduced to long-range shooting and although Green did manage to get one effort on target late on, Town keeper Scott Bevan just managed to hold on to the ball after fumbling.
Huddersfield were always dangerous on the counter attack after the break, but brave goalkeeping from Mark Tyler prevented both John Thorrington and Jon Stead from adding to the lead.
Wadsworth however, wasn't complaining, adding: "I think we just adapted better to the hot conditions, although it was one of the hottest days I can remember for a long time.
"It was always going to be difficult going to a side who had just lost at home, but we coped well with all their pressure and won the game by a great goal."
Posh boss Barry Fry moaned: "We struggled all over the place and there's no money around to strengthen. We have to improve."