Gary Roberts rued two points dropped despite Pompey fighting back to claim a remarkable draw against Morecambe.
The Shrimps stunned the Fratton Park crowd on Saturday by racing into a 3-0 lead after 38 minutes.
Tom Barkhuizen, Alan Goodall and Andy Fleming all struck to take advantage of a dreadful opening 45 minutes from the out-of-sorts hosts.
Then the comeback arrived, with Roberts scoring twice to reduce the deficit to 3-2 by the 65th minute.
Forced to play the final 18 minutes with 10 men following Enda Stevens’ red card, Paul Cook’s men piled on the pressure.
Fratton Park rejoiced when substitute Jayden Stockley headed home Adam Webster’s 95th-minute cross from the right.
But a frustrated Roberts was afterwards in no mood for celebrating snatching a late, late point.
He said: ‘You pick the bones out of it and you have to be positive.
‘We are unbeaten – but you have got to win your home games, you have got to win.
‘It doesn’t matter if you are playing the favourites for the league or teams like Morecambe who are not expected to go up, you have got to beat them.
‘You give them a 3-0 head start and it is hard to come back and you won’t succeed like that every week.
‘You can’t give three goals away to anyone at any level so we have to learn from that.
‘It didn’t feel like we took them lightly in the first half. We didn’t say “these are not good enough” and “he is not as good as us”.
‘We spoke about the right stuff, prepared right, did everything the same but sometimes it just doesn’t work.
‘It was a strange game. I thought Morecambe were good on the break.
‘You have got to take your hat off, they have some good players, players who have been about for years.
‘Jamie Devitt is a terrific player, these players can hurt you.’
Despite having 10 men for the last 18 minutes plus six minutes of stoppage-time, the hosts dominated the later exchanges.
Certainly Pompey’s numerical disadvantage was not obvious as the Shrimps defended for their lives under heavy examination.
Eventually the pressure produced Stockley’s first goal for the club via a flying far-post header.
And Roberts believes the Blues’ sprint finish was testament to the fitness levels boss Cook has instilled into his players.
He added: ‘We should have been going for the win really at 3-3 but the time ran out on us. To be fair, we were down to 10 men and Morecambe were blowing, you could see it in their team, they were getting behind the ball and blowing.
‘That is credit to our lads, that is when I think the fitness kicks in and when you have to take some positives out of it.
‘We worked really hard to get back into the game, created a few chances and looked like the only team trying to win the match, especially when it went to 3-3 and we were still pushing on.’
Pompey’s second successive draw puts them into sixth place in League Two after four games.
Tomorrow night they entertain Reading in the Capital One Cup at Fratton Park.