Erik Huseklepp netted another stoppage-time decider - but this time through his own net as Pompey suffered a harsh 3-2 home defeat to Peterborough.
The Norwegian, who struck a fabulous last-ditch winner against Blackpool at the weekend, raced back to prevent a late counter-attack, but could only put through his own net to send the Blues spinning to defeat.
Pompey fell behind in the fourth minute after a goalkeeping howler from Jamie Ashdown as he somehow allowed Lee Frecklington’s shot to squirm through his grasp and into the net.
But the home side hit back soon afterwards when Gabriel Akuani sliced into his own net after Huseklepp’s effort looked to be heading wide.
Darren Ferguson’s side took the lead again before the break as Frecklington hammered a fine finish beyond Ashdown.
Pompey were much-improved after the interval and dominated the game as Benjani netted the equaliser nine minutes after the restart as he converted Huseklepp’s cross.
It looked like there would only be one winner as Peterborough were forced to play on the counter-attack and only some great last-ditch defending kept Pompey at bay.
But the late sucker-punch arrived as a real body blow with Pompey trying to win the game only for Peterborough to snatch the points in dramatic style.