The Belgium international scored his second and third goals of the season, either side of Ross Barkley's first Goodison goal, as the Toffees routed the visitors in a one-sided first half.
Substitute Yohan Cabaye pulled a goal back within six minutes of the second half kicking off and Loic Remy's 89th-minute goal made it a more tense finish that it should have been for the hosts.
"Lukaku is a young man who has everything as a striker," said Martinez.
"Sometimes you see a number nine who is powerful and has a great physical presence - what Romelu brings is a real awareness around him.
"He is technically really gifted when he has his back to goal and that was a focal point today.
"He is a great goalscorer. He looked like a player who felt at home.
"I want him to enjoy his football, I want him to develop and become as good as he can."
There was surprise when returning Chelsea manager Jose Mourinho allowed Lukaku to go out on loan and that has been highlighted by the fact his league tally is already more than all the strikers at Stamford Bridge put together.
Fortunately for Martinez, the loan agreement is for a full season so there is no chance of an early recall.
Source: PA
Source: PA