In Wigan's dual battle to beat relegation from the Barclays Premier League, where they take on fellow strugglers QPR on Sunday, and win the FA Cup, Kone has been a revelation of late.
Since returning from African Nations Cup duty in February, the Ivory Coast international has scored six goals in his last six appearances, with Wigan winning all the matches in which he has found the net.
Given the striker cost a reported £2.7million upon his arrival from Levante in August, that now appears to be money well spent.
Martinez could not be happier with Kone as he said: "We've been very impressed at how he has settled in this league.
"For any striker that comes into the Premier League it takes time for them to get to know the physicality and tempo of the game, but right away he adapted really well.
"We then lost him to the African Nations Cup for a long period, but since he has come back there's been this real feeling he has been making up for lost time.
"For me he's a sensational footballer, a very important player for us. I would say he has been invaluable for us.
"As a character he's very quiet, he has this interior calmness and an inner confidence that is quite impressive. On the pitch he has this knack of making the right decision when it comes to scoring a goal.
"He's experienced different environments, such as the German, Dutch and Spanish leagues, and to come into the British game now, it is probably at the right time of his career. Although he is enjoying the best moments of his career, the best is still to come."