The Ivorian scored his first hat-trick in English football in the 6-2 demolition of struggling Sunderland to register a remarkable turnaround in the 31-year-old's fortunes.
After a knee injury decimated the first two years of his career at the club he was actually booed when he came off the bench in the season-opening draw at home to Watford.
The reaction was totally different after his sharp finishing put the Black Cats in their place after they had clawed back a 2-0 deficit.
"I had the privilege of working with him previously so I was an in an advantageous position and knew exactly what he could do," said Martinez.
"It was a really tough injury and I have seen players retiring from that.
"He got fit but then had a period of getting back to match fitness but no one in the training ground ever lost faith in him.
"He is a very important player for us in every aspect of his performances.
"It was a phenomenal 90 minutes because it triggers an extension to his contract (which was due to expire in the summer).
"He is a sensational example to any young footballer facing adversity."
Sunderland boss Sam Allardyce had considerably less belief in his players' ability to follow a plan as they threw caution to the wind chasing back-to-back victories when he thought they should have settled for a point at 2-2.
Jermain Defoe and Steven Fletcher both scored to cancel out the hosts' 2-0 lead given to them by Gerard Deulofeu and Kone but in an increasingly open game Everton picked them off with Kone scoring twice to complete his hat-trick after a Sebastian Coates own goal and one from Romelu Lukaku had already taken the result away from them.
"I am obviously concerned about the lack of understanding in certain periods of the game with the team, particularly when we got back to 2-2," said Allardyce.
"When we got the second we decided to go and attack for the third
We didn't get it and within seven minutes we tossed the game away and allowed Everton to score three silly, sloppy goals from counter-attacks they didn't have to work very hard for.
"That lack of discipline and understanding has really concerned me on the basis we should have been satisfied with the 2-2.
"At the top end we can score a goal and create chances but until we get into the habit of defending better out of possession it is worthless how many goals we score if we defend like that.
"That lack of discipline and organisation as a team is obviously the biggest concern for me."
Source : PA
Source: PA