The world number one advanced to the quarter-finals in just one hour and 16 minutes with a comfortable 6-4 6-2 victory over his fellow Spaniard.
Nadal had been taken to three sets in his previous match by unknown Italian Paolo Lorenzo - ranked 148th in the world, but was always in control against Lopez, breaking his serve four times in the match and achieving 88 percent first service rate and winning 81 percent of those points.
Nadal will now move on to the quarter-finals where he will face the winner of the match between 12th-seed Mardy Fish of America and of Marin Cilic Croatia.
