Bryn Morris saw his crucial mistake cast a shadow over his otherwise excellent Pompey showing against Southend.
The midfielder was in excellent form during the match on Saturday.
He scored the first Pompey goal and nearly had another as well when he struck the post which led to the third.
But in the end Southend profited from his tackle which conceded a pivotal penalty late in the second half.
That gave the home side a key route on the way back to salvaging a 3-3 draw from 3-0 down.
Kenny Jackett felt the pain of seeing Morris’ lively display tainted by the foul in the area.
The Pompey boss said: ‘There was that decision, but he’s made a good impression.
‘He’s scored a goal, hit the post and just impressed generally.
‘I think he’s impressed along with (Ben) Close in the past two games.
‘The mistake was a one-off decision with their man going nowhere.
‘It’s frustrating because it’s a key moment which has got Southend back into the game.’
Pompey have a chance to respond quickly when they host Bristol Rovers on Tuesday night (7.45pm).