A second half header by Archie Collins proved in vain as Accrington Stanley progressed into the second round of the Carabao Cup.
Posh were undone by a disastrous start to the contest at the Wham Stadium and the rest of the first half didn't get any better for Darren Ferguson's men as the League Two outfit were firmly in control.
Posh barely touched the ball before they conceded, as a long throw into the box on 37 seconds was flicked on invertedly by David Okagbue, Vicente Reyes made a smart stop but HENDERSON was there to bury the rebound.
The lead was doubled on 25 minutes as a close-range finish from MOONEY saw the ball find the back of the net. The home side had a flurry of bookings with Posh struggling to find any rhythm.
Harley Mills sent a free-kick just wide of the post from distance with debutant Lolos denied by Wright at the near post on the stroke of half-time.
Gustav Lindgren saw a shot on the turn pushed around the post by Wright on 54 minutes while Khela saw two goalbound efforts blocked.
Mills saw a free-kick find the side-netting via a deflection before Reyes made a smart stop after a low drive from Henderson.
Posh pulled a goal back on 80 minutes as substitute Cian Hayes picked out the onrushing Archie COLLINS who planted a header past Wright.
Reyes made two saves in stoppage time before the final whistle brought an end to the Posh Carabao Cup run.
Accrington Stanley: Wright, Sass, Rawson, Mooney, Henderson (sub Sinclair 40min), Pye (sub Love 61min), Matthews, Popoola (sub Woods 61min), Brown (sub Tunstall 77min), Martin (sub Coyle 62min), Conneely. Unused subs: Rogerson, Caton.
Posh: Reyes, Dornelly (sub Mendonca 70min), Mills, Wallin, Okagbue, Collins, Khela (sub Shofowoke 90min), O’Brien-Brady, Lisbie (sub Hayes 64min), Lindgren, Lolos (sub Odoh 46min). Unused subs: Smith, Nevett, Andrews.
Half-time: Accrington Stanley 2-0 Posh
Full-time: Accrington Stanley 2-1 Posh
Attendance: 847 (233 Posh fans)
Referee: Aaron Bannister