Late goals by Jim O'Brien and Matt Done earned Barnsley a win over Portsmouth that consigned the debt-ridden club to the Championship relegation zone.
A day after entering administration for a second time in two years, Pompey battled with 10 men following Dave Kitson's red card in the first half.
But they slipped to defeat when O'Brien struck from 20 yards and Done scored on the break in stoppage time.
Portsmouth's Joel Ward had a shot saved by Tykes keeper Luke Steele.
But Michael Appleton's side had few other meaningful efforts, and they are now without a win in four matches.
Following their 10-point penalty for entering administration, Pompey have a tough season ahead with Appleton only able to name three players on the bench for this game.
Their task at Oakwell was an uphill one after Kitson's soft red card for two bookable offences.
And they almost went behind as early as the fifth minute when Craig Davies controlled the ball on his chest and beat Pompey goalkeeper Stephen Henderson with a dipping 20-yard shot that rattled the crossbar.
Elsewhere in the first period, Portsmouth's Erik Huseklepp fired wide at the back post from just inside the penalty area.
But the biggest talking point came three minutes before the break, when Kitson went in late on midfielder Corey Smith and referee Eddie Idlerton wasted no time in showing the former Reading striker a second yellow card.
Ricardo Rocha almost gave Barnsley the lead when his header was bound for his own net before Henderson came to rescue to tip the ball around the post.
At the other end, Ward went close, but with time running the Tykes sealed the points when O'Brien found the bottom-left corner before Done fired in with a neat left-foot finish after racing clear.
Live Text Commentary
Full Time The final whistle is blown by the referee.90:00 +3:27 Booking
Booking Benjani Mwaruwari booked.90:00 +2:39
Scott Wiseman provided the assist for the goal.90:00 +2:39 Goal scored
Goal! - Matty Done - Barnsley 2 - 0 Portsmouth Matty Done finds the net with a goal from the edge of the penalty area to the bottom left corner of the goal. Barnsley 2-0 Portsmouth.90:00 +1:57
Unfair challenge on Erik Huseklepp by Korey Smith results in a free kick. Free kick crossed right-footed by Erik Huseklepp from left wing, clearance made by Scott Wiseman.90:00 +0:55
Short corner taken by Matty Done.89:51
Jason Pearce concedes a free kick for a foul on Craig Davies. Jimmy McNulty takes the free kick.87:07
Chris Dagnall is flagged offside by the assistant referee. Tal Ben-Haim restarts play with the free kick.86:16
Marko Futacs challenges Korey Smith unfairly and gives away a free kick. Stephen Foster delivers the ball from the free kick right-footed from right channel, Stephen Henderson makes a save.84:15 Substitution
Substitution Benjani Mwaruwari comes on in place of Ricardo Rocha.75:31
Korey Smith provided the assist for the goal.75:31 Goal scored
Goal! - Jim O'Brien - Barnsley 1 - 0 Portsmouth Jim O'Brien scores a goal from outside the area to the bottom right corner of the goal. Barnsley 1-0 Portsmouth.73:39
Rob Edwards challenges Marko Futacs unfairly and gives away a free kick. Free kick taken by Tal Ben-Haim.70:48
Jay McEveley restarts play with the free kick.70:48 Substitution
Substitution Scott Golbourne leaves the field to be replaced by Matty Done.70:48
Scott Golbourne fouled by Aaron Mokoena, the ref awards a free kick.69:50
Inswinging corner taken by Jim O'Brien, Jason Pearce makes a clearance.68:07
Outswinging corner taken right-footed by Erik Huseklepp from the right by-line, Scott Wiseman manages to make a clearance.67:50
Joel Ward takes a shot. Save made by Luke Steele.63:55 Substitution
Substitution Chris Dagnall joins the action as a substitute, replacing Andy Gray.
Short corner taken by Scott Golbourne.61:17
Free kick crossed left-footed by Jimmy McNulty from right channel, Jason Pearce makes a clearance.61:17 Booking
Booking Tal Ben-Haim goes into the referee's book for unsporting behaviour.61:07
Free kick awarded for a foul by Tal Ben-Haim on Jim O'Brien.59:01
Free kick awarded for an unfair challenge on Craig Davies by Tal Ben-Haim. The ball is swung over by Scott Wiseman, Headed effort from deep inside the area by Andy Gray misses to the left of the goal.58:17
Corner taken right-footed by Erik Huseklepp from the left by-line to the near post, clearance by Craig Davies.53:49
Corner taken by Scott Golbourne, Stephen Henderson makes a save.53:12 Booking
Booking Aaron Mokoena goes into the book for unsporting behaviour.53:09
Free kick awarded for an unfair challenge on Scott Golbourne by Aaron Mokoena. Jim O'Brien delivers the ball from the free kick right-footed from left wing, clearance made by Ricardo Rocha.51:54
Long distance effort from Erik Huseklepp misses to the left of the goal.50:56
Marko Futacs is penalised for handball and concedes a free kick. Rob Edwards crosses the ball in from the free kick, save by Stephen Henderson.49:32
Effort from just outside the area by Jim O'Brien goes over the target.49:07
Jay McEveley delivers the ball, Ricardo Rocha makes a clearance.47:05
Corner from left by-line taken by Erik Huseklepp.45:01
The second half has started.45:00 +2:57 Half time
Half Time The referee calls an end to the first half.45:00 +0:12
Andy Gray is flagged offside by the assistant referee. Indirect free kick taken by Stephen Henderson.44:01
Inswinging corner taken by Scott Golbourne, save made by Stephen Henderson.43:12
Effort on goal by George Thorne from just outside the penalty area goes harmlessly over the target.42:41
Tal Ben-Haim restarts play with the free kick.42:41 Booking
Booking Jay McEveley goes into the referee's book for dissent.41:41
Free kick awarded for a foul by Rob Edwards on Marko Futacs.41:12
Direct free kick taken by Luke Steele.41:12 Dismissal
Dismissal Dave Kitson is sent off.39:01
Dave Kitson gives away a free kick for an unfair challenge on Korey Smith.37:01
Free kick awarded for an unfair challenge on Craig Davies by Jason Pearce. The free kick is delivered left-footed by Jimmy McNulty from right wing, clearance made by Jason Pearce.27:54
Erik Huseklepp sends in a cross, Headed effort from deep inside the penalty area by Jason Pearce goes harmlessly over the crossbar.27:54 Substitution
Substitution Jay McEveley on for David Perkins.27:54
Rob Edwards challenges Marko Futacs unfairly and gives away a free kick.25:33
Free kick taken by Rob Edwards.25:33 Booking
Booking Dave Kitson is cautioned by the ref for unsporting behaviour.25:23
Dave Kitson concedes a free kick for a foul on Stephen Foster.20:34
Corner taken short by Jim O'Brien.18:53
Unfair challenge on Andy Gray by Ricardo Rocha results in a free kick. The free kick is delivered left-footed by Jimmy McNulty from left channel, George Thorne makes a clearance.18:09
Shot from just outside the area by Erik Huseklepp misses to the right of the target.16:36
Aaron Mokoena concedes a free kick for a foul on Scott Golbourne. Jimmy McNulty crosses the ball from the free kick left-footed from left wing, clearance by George Thorne.11:47
Free kick awarded for a foul by Jimmy McNulty on Joel Ward. Hayden Mullins takes the free kick.10:58
The assistant referee signals for offside against Marko Futacs. Rob Edwards takes the indirect free kick.10:47
Scott Golbourne sends in a cross, Tal Ben-Haim makes a clearance.8:13
Unfair challenge on Aaron Mokoena by Andy Gray results in a free kick. Stephen Henderson takes the free kick.5:33
Corner taken by Jim O'Brien played to the near post, save by Stephen Henderson.5:14
Shot from 20 yards from Craig Davies. Save made by Stephen Henderson.4:34
Aaron Mokoena crosses the ball, Header on goal by Dave Kitson from inside the box goes harmlessly over the target.3:39
The ball is crossed by Jimmy McNulty, Jason Pearce makes a clearance.2:54
Corner taken left-footed by Scott Golbourne to the near post, clearance made by Dave Kitson.0:00
The game gets underway.
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