Portsmouth first-team coach Ian Woan was full of praise for Kanu after the veteran striker netted the only goal in the 1-0 win over Barnsley at Fratton Park.
Second-half substitute Kanu scored six minutes from time by climbing highest to convert Greg Halford's cross.
Woan said: "There were a few raised eyebrows from the fans (when we brought him on), but you want your subs to make an impact.
"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."