The Chelsea winger adapted well to the request of his head coach Maurizio Sarri to play as a No 9, setting up both goals in the 2-0 win.
Martinez, Hazard's national team coach, was not surprised by the 27-year-old's selflessness.
"That's probably what people don't see," Martinez says. "Eden Hazard is a mature footballer. If he has to do something for the team he will do it.
"He did it in the World Cup with Belgium. Yes, he relies on individual quality in what he brings in the game, but he is a team player.
"As you saw [on Saturday] he was prepared to do something that he's not used to and doesn't do normally. But he's prepared to understand what he needs to do when the ball gets into his feet."
Martinez says Hazard has the attributes to lead the line whenever necessary, but expects him to return to his usual role at Brighton & Hove Albion on Sunday.
"He's someone who can hold the ball as well as any No 9, a target man," says Martinez. "He's got a really good centre of gravity.
"I'm sure Eden can play in different situations but that it was a one-off. You're not going to be facing Manchester City or the quality of Manchester City [every week]."