Hazard struck a hat-trick in victory over Newcastle United on Saturday.
"Eden is a great player, he has great confidence as well and anything he touches at the moment is going for him," Cahill told chelseafc.com.
"He's a young player getting better and at the moment he is producing some world-class football for us.
"In the first half when we didn't play particularly well and the game was quite tight, you want that little bit of individual brilliance and Eden produced that for us with two goals in which he was heavily involved in the build-up and he finished them.
"He has adapted to the league very well, he is a special player and he thoroughly deserved his hat-trick."