Lukaku has been outstanding on-loan at West Bromwich Albion this term.
Hazard said: "I was not surprised by the performance of Romelu. You have to remember what he had done in the Belgium championship at only 16.
"His first year at Chelsea may have been partly lost, because he was competing with Anelka and Drogba. Romelu was on a pedestal and was widely criticized. I'm glad for him this season, he managed to silence all critics.