The pressure was on the 83rd-minute spot kick awarded for a hand ball from an Andy Reid free-kick. The game was poised at 1-1 and regular taker Robbie Keane had made way for back-up taker Jermain Defoe.
But it was Mido who appeared most determined to take on penalty duties for the night and he made no mistake with his low drive to keeper Jamie Ashdown's left - although the Pompey keeper did guess right and got pretty close to making a connection with the ball.
However, Mido pointed out that him taking the kick was a no-risk strategy.
I am a penalty shooter and have taken five or six penalties for the national team
"On Monday I was the best player to take the penalty because Jermain had just come on and it is very dangerous to let a player who is just in to take a penalty - it would be an extra pressure while he is still not into the game.
"Robbie was off so I stepped up, took the decision and shot it in. For me, taking a penalty is not a pressure if you know what you are going to do. I put it as far away from the keeper as possible and 95 per cent of the time he has no chance of saving.
"He did go the right way but, with the pace of the ball, it would have been very difficult to get."
Mido insisted he didn't harbour a moment's doubt when it came to putting himself forward to take the crucial penalty against Portsmouth on Monday.