Pompey fell deeper into the relegation mire when they slipped to a 1-0 defeat to York today.
Michael Coulson’s fifth-minute goal was the difference between the sides, but Ben Chorley’s controversial dismissal five minutes after the restart proved crucial at Fratton Park.
The skipper was sent off for a tackle on Wes Fletcher after catching the striker, but the home crowd were angered by the decision.
The result means Richie Barker’s men are now three points and a single spot above the drop zone.
That is the bleak news ahead of a trip to league leaders Rochdale on Tuesday.
The importance of the game was obvious from a look at the table before kick-off.
Pompey found themselves a goal behind from the visitors’ first attack, as Coulson found a yard of space 20 yards out, swivelled and rifled a shot past Carson.
That rocked the home side who could have been further behind moments later, but Carson saved superbly from John McCombe’s angled drive.
The home crowd continued to back their team, though, and saw half-chances from Jake Jervis and Ryan Taylor saved by keeper Nick Pope.
The excellent Jed Wallace was at the heart of Pompey’s best play but scuffed a shot wide from a Jervis’ back heel.
There was applause and boos on the half-time whistle as the Blues went in 1-0 down.
Wallace had a good effort saved from a fine run moments after the restart.
The game swung on a key moment after 50 minutes though when Chorley was dismissed.
He was shown a red for his challenge on Fletcher which gave Pompey a mountain to climb.
Wallace was taking on York on his own and then had a 30-yarder saved.
Ryan Jarvis should have wrapped it up for the visitors with 17 minutes left but put his header wide from a free-kick.
It mattered little, though, with the 10-men huffing and puffing but able to create little over the finale.