Kenny Jackett felt Norwich defender Grant Hanley deserved to be sent off as Pompey advanced into the fourth round of the FA Cup.
The Canaries skipper received a straight red card in the 15th minute after bringing down Ronan Curtis at Carrow Road.
The Blues couldn’t capitalise on their extra-man advantage until stoppage-time, though, when Andre Green grabbed the only goal of the game.
There was some dispute whether it was harsh Hanley was given his marching orders for fouling Curtis.
Jackett reckons the referee made the right call, however, and was delighted with Pompey’s victory.
The boss said: ‘It's a great win for us and I'm pleased to progress through to the next round.
'Norwich made eight changes but it's still a buoyant and capable squad, and mostly important Carrow Road is a positive place to come to.
'To come here and win is something we're delighted with.
'The key moment obviously was the sending off early in the game.
'It was a red card and it looked like we couldn't capitalise on our chances opportunities and pressure until the key moment and I'm pleased for Andre.’