The midfielder made a barnstorming impact in Pompey’s 1-0 victory at the DW Stadium.
Introduced as a half-time substitute, Cannon needed just 36 seconds to make his mark when he crashed home an unstoppable effort into the top corner.
That proved enough to deliver the Blues a fourth successive League One victory and maintain Danny Cowley’s 100 per cent start as head coach.
Cannon was given instructions he was coming off the bench during the closing stages of the first period.
And the former Rochdale man bullishly told his team-mates that he’d settle matters with a piece of brilliance.
Cannon said: ‘It was a bit funny actually. When I was on the bench, I said to everyone: "If I come on them I'll wobble one top bins!"
‘I was laughing with them and ended up doing it.
‘It was a bit of a different game. It was tough so when you come on, you need a moment. Luckily, I did that and some of the boys have done that over the course of the season.
‘I knew I was coming. I was speaking to the manager at the end of the first half. When the whistle went, I asked him and told me I was still coming on.
‘I was just running with the ball and just thought: "Why not have a pop?"
‘The lads tell me to shoot more so I did and luckily it went in.’
Pompey have now moved up to fourth spot and momentum is growing in their bid for a play-off spot.
Cannon’s confident that the Blues can keep their place in the top six with eight games remaining.
‘I don’t see why we can’t finish in the play-offs,’ he said.
‘Looking at Christmas time, we were hoping to finish in the automatics but we're just taking it game by game.
‘Four wins on the bounce is good for the confidence and hopefully we have a good run-in.
‘Anything can happen in football but we’ll take it game by game and see where we are by the end of the season.’