Joe Gallen lauded a 'huge' result in Pompey's season.
With Kenny Jackett absent due to family issues, his assistant manager took the team for the 3-0 win over Oxford United.
Gallen acknowledged his side had to deal with pressure, until the game turned on Alex Mowatt's second-half penalty miss and red card.
He said: 'I thought Oxford played really well up to the penalty and the red card.
'I thought we started very well and had more of the play in their half with chances and crosses.
'We were playing well but they came back strong. That was no coincidence with the players they've got.
'There's no doubt it was a huge result at a vital time for us.'