Antoine Griezmann's deflected overhead kick gave the world champions the lead just before the half-hour mark and substitute Olivier Giroud wrapped things up with two close-range finishes late on.
But it is the first-half loss of Benzema to what appeared to be a thigh problem that will dominate manager Didier Deschamps' thoughts in the aftermath. Recently recalled after a six-year exile from the national team, the Real Madrid forward looked lively prior to his early departure, setting up Kylian Mbappe for a powerful shot that was well saved by Daniel Naumov.
Unfortunately for the Bulgaria goalkeeper, there was nothing he could do about an acrobatic effort from Griezmann shortly after, which took a nick off Ivaylo Chochev before hitting the back of the net.
Only more Naumov brilliance stopped Griezmann from doubling his tally before the break after a flowing team move, and he was also sharp in keeping out an Mbappe effort after the restart. But the latter should have done better than to drag a shot wide when played in one-v-one by Paul Pogba soon after.
Given the low-stakes nature of the fixture, it was no surprise France's dominance led to some understandable complacency, and they were handed a huge let-off when Birsent Karagaren shot wide after finding space in the area.
However, the win was effectively secured eight minutes from time when Giroud produced a trademark front-post finish from a delicious Benjamin Pavard cross. And the Chelsea forward was at it again in the final minute of normal time, tapping in an unmissable low ball across the box from fellow substitute Wissam Ben Yedder.
Standout matches today