The second-seeded Nadal was rarely challenged in his straight-set, 6-1, 6-3, 6-4 victory over Argentina's Eduardo Schwank. The Spanish great continued an impressive run at Stade Roland Garros in which he had dropped just nine games coming into the day's play.
He will next face another Argentine, Juan Monaco, who advanced with a strenuous 6-7 (5-7), 6-3, 6-7 (5-7), 6-3, 6-4 slugfest over Canada's Milos Raonic.
Nadal owns a 3-1 lifetime record against Monaco.
Meanwhile, the fourth-seeded Murray ousted Santiago Giraldo 6-3, 6-4, 6-4, and No. 6 seed Ferrer blew past Mikhail Youzhny 6-0, 6-2, 6-2.
Other winners Saturday included eighth-seeded Janko Tipsarevic and 12th-seeded Nicolas Almagro.