Meanwhile, Nadal, bidding for an astonishing sixth successive victory in the principality, was made to work harder to defeat fellow-Spaniard Juan Carlos Ferrero 6-4 6-2 in a match that was held up for 30 minutes because of rain and high winds.
Fourth seed Rafael Nadal beat fellow Spaniard and 15th seed David Ferrer 7-6 (7-5) 6-4 and will next face eighth seed Jo-Wilfried Tsonga, who trounced Juan Carlos Ferrero of Spain 6-2 6-2.