The Frenchman netted the winner in the 90th minute to help his side overcome Preston North End 2-1 in the third round of the Carling Cup and his performance was met with rapturous applause by his boss who has been thrilled with his attitude despite not getting a move away from the club in the recent transfer window.
"It is quite clear the talent Charles has got," Martinez said.
"The way he has acted since the window has closed has been an example for everyone.
"He has talent and many would pay money to watch him play football.
"More importantly he worked for the team extremely hard and, with his build-up towards the game, his day today has been sensational."