Dave Robertson masterminded a stunning victory over promotion chasing Sheffield United as two goals in the final few minutes from Jack Payne and substitute Conor Washington earned a stunning victory at Brammal Lane.
Goalkeeper Ben Alnwick made his first save on three minutes as he tipped over a fierce curler from Mark McNulty.
Bob Harris curled a shot just over the right upright moments later as the Blades made a fast start. Kyle Vassell fired a shot into the side netting following a fine pass from Newell at the other end, but the angle was tight and there was not much for the former Bishop's Stortford man to aim at.
Alnwick denied Murphy with his legs on 16 minutes after a good advantage from referee Oliver Langford caught Posh out. Alnwick made a routine stop to deny Doyle moments later.
Captain Payne went into the referee's book on 23 minutes for his second foul of the game. A superb Taylor cross picked out Vassell at the back post on the half hour mark, but he couldn't guide his effort on target.
On 36 minutes, Vassell lifted a shot over the bar after good pressure from Bostwick saw a turnover in possession. Vassell went into the book before Ntlhe saw a shot parried by Turner rather unconvincingly.
Two minutes of stoppage time at the end of the first half was signalled by the fourth official, but apart from a wayward Payne volley, there was nothing to report on.
Former Posh midfielder Paul Coutts was replaced at the interval with Jason Holt introduced. Vassell had two chances on 50 minutes, his first was weak and collected by Turner, the second was over the bar.
Posh made a change on 55 minutes with Conor Washington replacing Vassell in attack. On 65 minutes, the Blades opened the scoring and it was a mistake by Santos who tried to be clever under pressure from DONE, his initial shot was parried by Alnwick but the striker nodded home the rebound.
Skipper Payne struck the outside of the post on 74 minutes after Bostwick's crunching tackle in midfield saw Murphy dispossessed.
Aaron Mclean replaced James with 10 minutes to go as Posh pressed for a deserved leveller. Newell saw a goalbound shot blocked by Harris before a Taylor cross caused havoc.
On 88 minutes, Posh drew themselves level as skipper Jack PAYNE unleashed a fierce right-foot shot that nestled in the bottom corner past the despairing dive of goalkeeper Turner.
Incredibly as four minutes of added time, Posh scored again as a Mclean flick on was read by WASHINGTON who burst past two challenges and fired a stupendous shot past Turner and into the corner.
Doyle clipped the top of the bar at the other end as Posh failed to clear a corner kick.
Full-Time: Sheffield United 1-2 Peterborough United
Sheffield United: Turner, Harris, Brayford, Basham, Flynn, Doyle, Murphy, McNulty (sub Reed 63min), Done (sub Freeman 81min), Coutts (sub Holt 46min), McEveley. Unused subs: Alcock, Williams, Adams, Calvert-Lewin.
Posh: Alnwick, Ntlhe, Santos, Zakuani, Smith, Taylor, Payne, Bostwick, Newell, Vassell (sub Washington 55min), James (sub Mclean 85min). Unused subs: Henry, Burgess, H. Anderson, Beautyman, Norris.
Attendance: 18,604 (417 Posh fans).