Portsmouth's first-team coach Ian Woan labelled Kanu 'a magician' as Barnsley manager Mark Robins lamented the nature of the Nigerian's goal.
Kanu came off the bench to score the only goal for Pompey on 84 minutes and earn his team a first Championship win at Fratton Park since October.
Woan acknowledged Kanu is no longer capable of playing a full game, but believes the striker still possesses the talent to decide games.
"There were a few raised eyebrows from the fans (when we brought him on), but you want your subs to make an impact," said Woan.
"He's an absolute magician. You see him day in, day out on the training pitch and some of the things he does with the ball are phenomenal. He's a top, top professional given where he has played and the enthusiasm he gives us every week in training.
"His legs can't carry him for 90 minutes sometimes now. But in a game that is crying out for someone to get hold of it, you throw the big fella on and he is a magician.
"You can't get the ball off him. People get to the stage where they don't want to go and challenge him. He embarrasses you.
"The whole stand starts cheering, he does the step-overs - you know they're coming but you can't do anything about it. We just didn't have that and he was perfect for the situation."
On picking up a second straight clean sheet, Woan added: "I think it's a major plus for us. We have struggled to keep clean sheets.
"The back-line in the last two games has been the same. That has made a big difference. We've done a lot of work with them on the training field.
"Continuity is a big thing with the back four. You need to know what everyone is doing. When you pick the same back four, it makes a big difference to them."
Barnsley boss Robins was left disappointed with the goal his side conceded, saying: "To concede the goal we did in the manner we did was poor. I was shouting on from the side because I could see what was coming.
"It was a poor goal to give away. A point down here would have been a decent point and set us up for Tuesday night's game (at Leeds).
"The free-kick that resulted in the goal was a little bit harsh I think. But we haven't defended properly. We conceded a goal late on and left a difficult way back."
Robins admitted his team lacked attacking verve and claimed they lacked confidence in their ability to score.
He said: "We threw bodies forward but we lacked ideas up front. We didn't look like we were going to score a goal.
"It's about the players understanding what's required of them when they go on to a football field. They need to get it into the right areas and give the team a lift.
"We need to score a goal away from home earlier, which gives us a little confidence and something to build on. It looked as if we were just hoping we might get a goal, rather than going out and making it happen.
"That, for me, has been symbolic of the season away from home. We need someone to get hold of the game by the scruff of the neck and make things happen for the team."