Pompey are staring into the League One abyss after defeat to Millwall.
Harry Kane’s 37th-minute strike gave the Lions a 1-0 win on a painful night at Fratton Park.
That leaves Michael Appleton’s men nine points from safety and needing a miracle to remain in the Championship with four games remaining.
Pompey can now be condemned to League One at Doncaster on Saturday if results don’t go their way.
The reality was Pompey looked increasingly edgy and short on ideas after a high-tempo start failed to yield a return.
The decisive moment arrived eight minutes before the break when Kane turned and fired home from the edge of the box.
Fratton was ready for a second-half onslaught, but it never arrived as Appleton’s side became more and more edgy.
Jason Pearce and Kelvin Etuhu had shots well saved by Maik Taylor.
Then Chris Maguire had a half-decent appeal for a penalty turned down as he was challenged by Jack Smith.
But the goals didn’t arrive and Pompey now look certainties to be relegated.