Andy Awford lauded the team spirit which has lifted Pompey into second spot.
Craig Westcarr fired the Blues to a late 1-0 victory at Oxford United on Saturday.
It was a fourth successive triumph and a third on the spin in the league as they maintained an impressive start to the campaign.
For many present, though, it was a below-par Blues showing against a U’s side managed by ex-Fratton boss Michael Appleton.
Nonetheless, Pompey ran out winners to climb up to second place in League Two.
And Awford is adamant his side’s unflagging spirit saw them past the threat of Oxford.
He said: ‘The players have got spirit, that is one thing they do possess – and they keep going.
‘When I walked through the door one thing I made clear was they had to give their absolute everything – and they do.
‘If they don’t they won’t play, it’s as simple as that, they know that and that is how it is.
‘On Saturday and in every game we’ve had this season I’ve had 125 per cent out of every single player.
‘I keep going on about this, it’s not just the 18 in the match-day squad it’s everybody.
‘For instance, Adam Webster did not made the squad but was jumping up and down (in the dressing room).
‘They are all in it together and that is a fantastic thing we want.
‘We’ve got good strength in depth and there’s certainly a good team spirit.
‘I’m not just saying the spirit won it for us against Oxford – we played some football as well – but you need it.
‘We are not always going to have it our own way and pass the ball and win three or four nil, that is not going to happen every week.
‘You have to come away and win ugly sometimes.
‘It was a bit ugly first half but in the second half I thought we played really well.
‘But you have got to have your team spirit – if you don’t, I believe you won’t win anything and we have got that in abundance.’
Appleton’s men struck the post in the first half through Danny Hylton and the striker also had strong penalty appeals waved away.
It left the former Pompey boss still searching for his first point since taking over last month.
And Awford admitted his team were given a test by the hosts.
He added: ‘It was a tight game.
‘They are a good side and pass the ball really well.
‘I have watched their last three games on DVD and I think they have been unfortunate in the previous three games not to do something.
‘They have good shape, I know Michael (Appleton) really well and he plays it the right way.
‘We just needed to keep the ball better in the second half – and we did.’