Blues fall to narrow defeat at Portman Road.
A second-half own goal from Mark McGuinness was enough for Posh to grab three points.
Jonson Clarke-Harris missed a first-half penalty in a game of very few chances.
The Arsenal loanee attempted to clear his lines, but skewed his clearance into the bottom right corner of his own net in the game's only goal.
Town were dealt a blow with new recruit, Josh Harrop testing positive for Covid-19 yesterday, meaning he will miss the next two games also.
Paul Lambert made one change from last weekend’s win at Burton as Aaron Drinan replaced James Norwood who couldn’t shake off a hamstring problem. Luke Thomas was named amongst the substitutes.
Blues were enjoying much of the early possession and play, and had the first opening of the game, after good work from Teddy Bishop to win a free-kick on the corner of the penalty area. From the resultant set-piece, Alan Judge worked the ball to Bishop in a rehearsed routine, but the Blues midfielder’s strike was deflected behind by Clarke-Harris.
Posh had their first attempt of the afternoon with 25 minutes on the clock as Clarke-Harris lashed a free-kick from 30-yards out just over the crossbar.
The visitors were beginning to grow into the game and Sammie Szmodics found Siriki Dembele with a clever through ball, but the Posh forward’s strike from a tight angle inside the box was tipped behind by Tomas Holy.
The lively Dembele was slipped through again on 32 minutes by Jack Taylor and was brought down by Toto Nsiala inside the penalty area. Referee Antony Coggins eventually pointed to the spot, but Clarke-Harris stepped up and blazed his powerful spot-kick over the bar. Let off for Blues.
Just before the break, Dan Butler’s dangerously whipped free-kick from the right touchline was begging to be turned home by a Posh player, but it evaded everyone to go behind for a Blues goal-kick.
The opening 15 minutes of the restart were uneventful, with Butler producing Peterborough’s first shot on target from a low free-kick which Holy gathered at the second attempt.
The deadlock was broken after 69 minutes from a Butler cross which McGuinness sliced into his own net from inside the six-yard box leaving Holy rooted to the spot.
Blues made a triple change on 74 minutes with Thomas coming on for his debut, along with Freddie Sears and Jon Nolan who were also thrown into the action to try and salvage something from the game.
With his first touch of the ball, Nolan forced Christy Pym into a smart stop with a well-struck effort from 25-yards out.
As snow began to descend down onto Portman Road, Gwion Edwards was inches away from an equaliser for Town. The ball fell kindly to the Welshman at the far post and he cut in to move the ball onto his right-foot and unleashed a fierce strike which almost crept into the top right corner.
Posh substitute Ethan Hamilton almost doubled the visitors lead, after another delivery from Butler from the left found the midfielder inside the box, but his cushioned effort was just wide of the mark.
Town had the ball in the back of net in added on time through Nsiala, but is was chalked off as the ball had already gone out of play before Luke Chambers had headed the ball back to his fellow defender.
Posh held on to claim three points in a game that lacked chances, with Blues dropping a place to 9th in the table.
Town: Holy, Chambers (C), Nsiala, McGuinness, Ward, Dozzell, Downes, Bishop (Nolan 74), Judge (Thomas 74), Drinan (Sears 74), Edwards.
Subs: Cornell, Woolfenden, Kenlock, Huws, Sears.
Peterborough: Pym, Butler, Thompson, Beevers (C), Kent, Taylor, Clarke-Harris, Dembele (Mason 88), Brown (Hamilton 81), Szmodics (Jones 84), Kanu.
Subs: Gyollai, Eisa, Broom, Burrows.
Booked: Taylor, Ward, Edwards, Burrows