The result condemned Pompey to their third successive defeat.
But Ben Close took many positives from the Blues’ 1-0 loss against Bradford City at Fratton Park on Saturday.
The performance from Kenny Jackett’s troops was one of the strongest since the 55-year-old was appointed manager in June.
Pompey did everything but put the ball in the back of the net against one of the best sides in League One.
The Blues should have had the game wrapped up shortly after half-time.
Kyle Bennett missed a hat-trick of opportunities, while Close and Matty Kennedy had efforts adeptly saved by Bantams goalkeeper Colin Doyle.
The hosts were caught out by an 80th-minute sucker-punch when Matthew Kilgallon was left free inside the box and glanced home Tony McMahon’s free-kick.
Close admitted the loss was tough to take and is adamant Pompey should have got something out of the game.
He said: ‘As players and staff, we felt we did play well.
‘There was just one slip of concentration and we got punished for it.
‘That’s why Bradford are probably so high up in the table.
‘They sniff chances out like that and they punish teams.
‘The lads are gutted but at the same time we know we played well.
‘From open play, they didn’t really look like a threat.
‘We defended in all areas of the pitch and the performance was excellent for 99 per cent of the game.
‘To concede like that is obviously a big blow, but we’re going to take that and move on.’
Before Saturday, Jackett’s men previously fell to back-to-back losses at Doncaster and Blackburn, where both performances were deemed below par.
Nonetheless, the effort against Stuart McCall’s troops highlighted Pompey can go toe-to-toe with the top teams.
The Bantams reached the play-off final last season and they harbour automatic promotion ambitions this campaign.
Despite Bradford escaping Fratton Park with all three points, Close revealed the atmosphere in the Blues’ dressing room after the final was more upbeat than it has been in recent weeks.
The former Eastleigh loanee believes that was due to the manner of the performance compared to losses at Ewood Park and the Keepmoat Stadium.
‘Morale depends on how you get beaten,’ Close added.
‘Obviously, no player likes losing matches.
‘But losing the way we did against Doncaster – which was a flat performance – we were disappointed with that.
‘Losing to Blackburn by three goals was disappointing as well and it was always going to be hard to pick up points there.
‘On Saturday, it was disappointing that we lost but at least we can say we had a right go at it.
‘We were excellent for 99 per cent of the game.
‘Defensively, we were really solid for most of it.
‘There are lot more positives to take into the next game.’