The Scot said: "Christian has been excellent. You run out of things to say about the big guy.
"He has turned himself into a fans' favourite here, that's for sure, and his general game is outstanding at the minute.
"He has been brilliant for us. I thought the header for the winner against Reading was fantastic.
"You forget he is only 21 and he might not hit his peak until his late 20s but he is playing ever so well for us."
Benteke is used as the only out and out striker in a 4-2-3-1 formation and Lambert said: "You've got to be a special type of player to play that lone striker role.
"He has also been fantastic for Belgium and he is getting better with every game.
"He is developing his whole demeanour...he is growing up. he is a strong lad but also has really good ability.
"He does get on the end of chances. I've been delighted with him."