Guy Whittingham praised the fighting spirit of his Pompey side despite their 2-0 defeat to Chesterfield.
Two goals in the final three minutes condemned the Blues to a defeat, having spent most of the match down to 10 men.
David Connolly saw red for his reaction following a hotly-disputed second penalty shout and is now banned for three games.
But for Whittingham there were still plenty of positives to come out of the game.
‘I think probably the referee is the only one that didn’t think it was a penalty,’ he said.
‘Even their staff have said it was a stone wall.
‘David Connolly has apologised for his sending-off, decisions didn’t go for him but that is no excuse.
‘We showed fight and spirit in the team and you could see that the fans appreciated that.
‘And for that reason I feel encouraged by the result.’