It was the moment of madness from Mark Roberts which changed the course of the match.
And Christian Burgess is convinced referee Seb Stockbridge made the correct decision to dismiss Cambridge United’s skipper.
Following the half-time whistle, Roberts was involved in a scuffle with Pompey assistant manager Leam Richardson, before knocking over Aaron McCarey.
The hosts had been leading 1-0 at the time – yet neither Roberts nor Richardson reappeared after the break having been served red cards.
The Blues went on to claim a 3-1 victory against the 10-men, with Matt Tubbs scoring twice and a Leon Legge own goal settling the contest.
Afterwards Cambridge boss Richard Money launched an angry verbal attack on Richardson and Pompey over the half-time incident.
Yet Burgess was adamant Roberts’ punishment was warranted.
He said: ‘The sending off had an impact obviously, in the game there were swings and roundabouts and a couple of quality moments, as well as plenty of talking points.
‘At half-time I didn’t know what happened first because I was walking off and turned around to see our assistant and their centre-half (Roberts) involved in some kind of a fracas.
‘Then I saw their centre half throw Aaron to the floor.
‘I thought “Blimey, the referee is there, it is under his nose, you can’t be doing that on the football pitch”.
‘Their centre half saw red, I suppose, and reacted. Aaron was just trying to split them up and in the end the referee has sent Roberts off and it was probably the right decision.
‘When we got into the changing room, a few minutes after that somebody said Roberts had been sent off.
‘We had already started our team talk.
‘Regardless, it was pretty much the same message, to keep doing what we are doing, try to get the ball wide, get crosses in and create. We believe that way of football will get results.
‘I didn’t even know Leam had been sent off until after the game, I didn’t realise!
‘It gave Cambridge a bit of knock and maybe gave us a boost of confidence. We found a lot of space and controlled the second half and it was a bit of attack versus defence.
‘They didn’t have as many balls sticking up top as they went to one up front. You could also see they were tired, teams chase a lot in the first half and you could see us getting stronger in the second half.’
There was also controversy over Cambridge’s opener, when Robbie Simpson was flagged for offside.
The linesman then put his flag down and the goal stood – much to Pompey’s annoyance.
Burgess added: ‘The lad was offside and we all stopped when we saw the flag go up.
‘We saw them celebrating so I ran over to the linesman and the referee said “It has come off a blue”.
‘I tried to argue but once he made his decision he wasn’t going to change that. He was convinced I got the last touch and I was convinced I didn’t.
‘The referee overruled the linesman, but that’s football. We went on to win anyway.’