The Real Madrid forward had previously gone 1,222 minutes without a goal for his country before ending the barren spell against Australia last October.
Now, the former France coach feels that the 26-year-old has kicked on and claims that he can be categorised with the world's elite players.
"He is always the scorer. But he has improved with his teammates," Houllier told Journal du Dimanche.
"He is now falling into the category of world-class players. Ronaldo, Messi, [Robin] Van Persie, [Arjen] Robben and [Luis] Suarez are perhaps a little above him.
"But he is younger. The goal against Australia has done him good. [Coach] Didier [Deschamps] played an important role during the period of drought, which all attackers go through."
Benzema and co face Ecuador in their final Group E game on Wednesday.