Crawley Town slipped back into the bottom four after losing 4-3 away at Peterborough.
Reds looked like they had done enough to secure a valuable away victory and held a 3-2 lead with just three minutes to go through goals by Marvin Elliott, Mathias Pogba and Josh Simpson
However Peterborough responded with two goals in the last three minutes by former Crawley player Michael Bostwick and Conor Washington to complete a late comeback.
Reds made one change to the side which beat Notts County 2-0 with Elliott recovered from a shin injury returning in midfield.
He replaced Anthony Wordsworth, who has returned to Ipswich at the end of his loan spell.
Bobson Bawling was named on the bench in place of Ryan Dickson who has a groin strain.
Peterborough included ex-Reds’ youth teamer Harry Anderson and 16-year-old schoolboy Da Silva Lopes who made his full debut.
Peterborough started brightest with Marcus Maddison, Leo da Silva Lopes and Harry Anderson all testing Brian Jensen.
Crawley’s only early chance came for Pogba who headed a cross by Gavin Tomlin wide.
Elliott gave Crawley the lead in the 29th minute at the end of a fine move involving Simpson, Gavin Tomlin and Pogba which was pulled back by Izale McLeod for Elliott to slam into the top of the net from close range.
Peterborough’s Washington threatened the Reds goal with a low shot which was again well saved by Jensen.
The Posh equalised two minutes before half-time when topscorer Washington reacted first on the rebound to Bostwick’s 30-yard free-kick which hit the post.
Bostwick gained ‘Boro the lead early in the second half with a superb 25-yard shot which gave Jensen no chance.
Crawley then made a brilliant recovery by scoring two goals in three minutes to the delight of their sizeable army of travelling fans.
McLeod set-up Pogba to score his first goal for the club, with a well-taken cushioned volley.
McLeod was provider again in a move which regained Reds the lead on the hour nicely put away from the left by Simpson.
But the action was far from over and Peterborough responded with two more goals.
With just three minutes to go Bostwick hit a belter in off the post from just inside the penalty box.
Then Washington netted the 90th minute winner from six yards after Jonathan Edwards headed Maddison’s cross against the post.
Crawley Town: Jensen; Young, Ward, Bradley, Youga; Simpson (Oyebanjo), Elliott, Fowler, Tomlin; Pogba, McLeod (Smith). Subs: Price, Bawling, G.Edwards, Morgan, Harrold.
Peterborough United: Alnwick, Smith, Bostwick, Oztumer, Washington, Newell (Payne), R.Santos (Burgess), Zaukani, Anderson, Maddison, Da Silva Lopes (J Edwards). Subs: Henry, James, Norris, Beautyman
Referee: C Breakspear