Richie Barker praised his side’s desire after fighting back against Mansfield and coming close to then claiming victory.
Ryan Taylor’s strike on his home debut cancelled out Lee Stevenson’s 50th-minute opener to secure a 1-1 draw at Fratton Park.
The Blues striker’s 78th-minute goal was conjured up by substitute David Connolly, who had earlier struck a post.
In a strong late charge from the hosts, Patrick Agyemang missed his kick from six yards out, while Jake Jervis had strong appeals for a penalty turned down.
It was in complete contrast to a lacklustre opening 45 minutes and Barker was pleased with his team’s response.
He said: ‘There were 15 minutes where we lost our way a little bit in the second half but I am full of praise for the way the players came back and their desire to make sure they didn’t lose the game.
‘I don’t think we played poorly for most of the game and for the last half-an-hour we were fantastic.
‘Unfortunately, by then it took us until we went a goal down for that to happen.
‘We needed to be positive (with substitutions) and sometimes people just assume by throwing forwards on you can score.
‘But you have to look at where the supply is going to come from, so we asked David Connolly to do something a bit different and link up for us and I thought he was fantastic when he came on.’