Robert Huth put Leicester ahead after just six minutes, heading in Christian Fuchs’ long throw.
Leicester striker Jamie Vardy then netted a second seven minutes after half-time from a breakaway, but Yohan Cabaye fired for Palace two minutes later.
It was left to Benteke to nod in Andros Townsend's cross at the far post to claim a point for Palace.
That moved them above AFC Bournemouth into 15th on 35 points, seven off the bottom three. Leicester are 12th on 37 points.