Nadal, seeking to collect his first U.S. Open championship, advanced to the Round of 16 where he will take on countryman Feliciano Lopez, who defeated Sergiy Stakhovsky 6-3, 4-0 after the Ukrainian retired with an infected toe.
Murray, meanwhile, was victimized by No. 25 seed Stanislas Wawrinka, who rallied after dropping the first set to take a 6-7 (3-7), 7-6 (7-4), 6-3, 6-3 victory over the Scotsman.
Wawrinka now will attempt to make his first Grand Slam quarterfinal appearance when he takes on 20th-seeded American Sam Querrey, who served up 19 aces in his 6-3, 6-4, 6-4 triumph over 14th-seeded Spaniard Nicolas Almagro.
Also Sunday, eighth-seeded Fernando Verdasco handled Argentina's David Nalbandian 6-2, 3-6, 6-3, 6-2, and 10th-seeded David Ferrer breezed past Daniel Gimeno-Traver 7-6 (7-2), 6-2, 6-2.
Ferrer now goes on to face Verdasco.
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