Matt Clarke felt it was two points dropped for Pompey after they were held by Burton Albion.
The Blues were forced to settle for a 2-2 draw against the Brewers at Fratton Park.
Kenny Jackett’s men were the better team against Nigel Clough’s visitors and should have gone into half-time with more than a 1-0 lead. Oli Hawkins opened the scoring on 36 minutes.
Burton swiftly turned the game on its head within seven minutes of the second period, however, with Devante Cole and Joe Hesketh scoring.
Clarke’s 57th-minute header levelled but Pompey were unable to find a winner.
The draw cut the Blues’ advantage at the summit of League One to four points – after Peterborough’s defeat of Fleetwood.
And Clarke admitted it was a game Jackett’s men should have won.
The centre-back said: ‘You have got to say it’s two points dropped.
‘In the first half, especially, we got into some pretty good areas, putting balls into the box.
‘To go into half-time 1-0 up you’d obviously take but it could have been more.
‘Maybe it didn’t quite fall for us. The one we did score was a good goal and a great finish but there weren’t any other chances where you thought “that’s a sitter”.
‘The ball seemed to fall to their defenders rather than our attackers. That’s maybe sometimes how it goes.
‘Burton only really had that spell after half-time.
‘We’ll look at it as two points dropped but maybe that’s because it’s where we are this season.
‘We feel like we can win every game but, especially now, we’ll look back and think we could have won it.’
Clarke was frustrated how Pompey conceded two quick goals in the second half to allow Burton back into the game.
He believes both were preventable – and insists the Blues will learn from it.
‘They worked their first goal well,’ Clarke added.
‘They got an overload down our right, put a good ball in and it was a tidy finish.
‘But with every goal there are always ways to pause it, look at it after and stop it from the source.
‘For their second goal, he (Hesketh) gets it from the throw-in. That’s poor itself.
‘That’s how high our standards are, we don’t want people to get the ball from throw-ins.
‘I’ve tried to read it and he’s gone past me, a couple of others and put it in from a tight angle.
‘It wasn’t a good goal to concede all round and not been like us. Hopefully we can deal with it, learn from it and move on.’