by Neil Weld at Oakwell
Pompey dropped into the Championship relegation zone after suffering defeat at Barnsley.
It was always going to be a difficult afternoon for the Blues – who could only name three players on the bench – once Dave Kitson was sent off late in the first half.
But the visitors were comfortably holding on for a point until Jim O’Brien struck 14 minutes from the end.
Matt Done then added a stoppage-time second for the Tykes after Pompey had committed men forward.
Michael Appleton made three enforced changes from the side that were beaten by Ipswich on Tuesday night.
Greg Halford (knee), Liam Lawrence (calf) and Kelvin Etuhu (hamstring) all missed out after picking up injuries against the Tractor Boys.
George Throne came straight into the midfield after completing his loan switch from West Brom earlier in the day, while there were also starts for Aaron Mokoena and Kitson.
The sides traded half-chances in the opening few minutes, before Tykes striker Craig Davies let fly with a shot from distance that looped onto the crossbar.
But there was not too much to lift an Oakwell crowd that was very subdued – apart from around 600 noisy travelling fans.
Those Pompey fans almost had something to celebrate on 19 minutes, though, as Erik Huseklepp dragged a shot just wide after Joel Ward’s cut-back had found him on the edge of the box.
Kitson was then in the action – although not in the way he would have wanted – shown a yellow card for flooring Stephen Foster.
And the striker’s afternoon got a whole lot worse on 42 minutes when he was booked again for a high challenge on Korey Smith and then shown a red card by referee Eddie Ilderton.
Half Time: Barnsley 0 Pompey 0
Pompey made the brighter start to the second half, with Thorne just failing to meet Huseklepp’s corner before the Norwegian fired wide after Hayden Mullins had done well to steal possession.
But it took a fine save from Stephen Henderson to keep the scores level on 54 minutes. The Irish keeper just managed to push the ball clear after Ricardo Rocha had sent a header flying towards his own goal.
Like the opening 45 minutes, however, chances were at a premium and the Blues back-line were doing a good job of protecting their goal.
And it was Pompey players who were providing Barnsley’s best chances, with Mullins hooking a clearance straight into Henderson’s arms.
The visitors were not causing too many problems at the other end, but Appleton would have been pleased to see his side looking solid at the back.
But the Blues’ defence was finally breached on 76 minutes when O’Brien let fly from 20 yards with a shot that swerved wickedly on its way into the net.
Rocha then bravely got in the way of Davies’ fierce strike from the edge of the box as Barnsley looked to strengthen their lead.
That was the Portuguese defender’s last moment of action, as he made way for the more attack-minded Benjani seconds later.
But it was Barnsley who scored deep into stoppage-time. The hosts broke quickly from a Pompey free-kick and substitute Done slid the ball past Henderson.
Barnsley: Steele; Wiseman, Foster, Edwards (c), McNulty; O’Brien, Smith, Perkins (McEveley 29), Golbourne (Done 72); Davies, Gray (Dagnall 65)
Goals: O’Brien 76, Done 90+3
Booked: McEveley
Subs not used: Preece, Cotterill
Pompey: Henderson; Mokoena, Rocha (Benjani 85), Pearce (c), Ben Haim; Ward, Mullins, Thorne, Huseklepp; Kitson; Futacs
Sent off: Kitson (two yellow cards)
Booked: Mokoena, Ben Haim, Benjani
Subs not used: Ashdown, Webster
Referee: Eddie Ilderton
Attendance: 9,336 (618 Pompey fans)