The first set went with serve for 11 games, with both men missing out on break-point opportunities, before Ferrer cracked the Llodra serve and took the set 7-5 in 70 minutes.
The second was a much simpler affair for the world number five. He raced into a 4-0 lead thanks to a pair of breaks before Llodra gave the home crowd something to cheer about by breaking back to-love in the next.
The left-hander could not complete the comeback, however, as Ferrer held serve in the ninth game and sealed the win with a forehand winner at the net.
The Spaniard will take on surprise package Jerzy Janowicz, who has knocked out the likes of Andy Murray, Marin Cilic and Janko Tipsarevic in the French capital.