Joey Barton claimed referee Lee Swabey ‘cost’ Fleetwood following a Fratton Park defeat.
Oli Hawkins grabbed Saturday’s only goal, heading home in the 50th minute after a Dion Donohue corner.
It extended Pompey’s lead at the top of League One to six points as they maintain their impressive start.
Barton, however, was upset with the 84th-minute sending off Nathan Sheron following a second bookable offence, both incidents coming on Ronan Curtis.
And despite failing to register a shot on target, he laid the blame on Swabey.
Barton told fleetwoodtownfc.com: ‘It was a pretty even match, with both sides cancelling each other. We have come to a place with 18,000 fans and it was silent for the majority of the game.
‘It looked to be a set-play game, where you have two good sides competing and the key is to make the most of those opportunities when they arrive.
‘On the whole, I thought the officiating team were poor. We got a player booked for taking too long a throw-in, where they have a player who took at least double the amount of time; and he didn’t get booked.
‘Young Nathan Sheron was sent off for winning the ball – bizarre. Everybody in the stadium apart from the referee, fourth official and linesman on our side see that Nathan won the ball clearly, yet he was sent off.
‘We can’t appeal that as it was a second yellow card, which for us is ridiculous.
‘As I’m finding at this level, the officiating leaves a lot to be desired. They (the referees) have to be more consistent.”
‘He (Sheron) was solid and I’m devastated for him to be sent off for what is a ridiculous decision. He’s disappointed because he’s worked hard to get into our starting 11 and now he understands that we can’t appeal a wrong decision, he doesn’t have the ability to play against Peterborough on Tuesday.
‘Not only has the referee cost us, but he’s certainly going to cost us on Tuesday night.’
Now Fleetwood must head to Pompey’s promotion rivals Peterborough, seeking to bounce back.
Barton added: ‘We knew it was going to be a tough week. We’ve come to the first away, and now the second away is on Tuesday, we’re in every fight.
‘I said to the lads that we can’t want for the lack of effort – clearly we needed a little bit more quality on Saturday.
‘But saying that, we could be saying that for both teams, because if we would have won 1-0 it would have been the same thing.’