NEW YORK, Sept. 1 (UPI) --
World No. 1 Novak Djokovic
and third-seeded defending champion Andy Murray
each breezed into the round of 16 with wins Sunday at the U.S. Open.
Djokovic routed Portugal's Joao Sousa in 6-0, 6-2, 6-2 fashion on the hard courts at the USTA Billie Jean King National Tennis Center.
His next foe will be Marcel Granollers of Spain, who bested the last remaining American, Tim Smyczek, by a 6-4, 4-6, 0-6, 6-3, 7-5 margin.
Meanwhile, Murray, seeking to claim back-to-back major wins following his historic victory at Wimbledon in July, downed his German opponent 7-6 (7-2), 6-2, 6-2 in 2-hour match at Arthur Ashe Stadium.
The Briton, who bested Djokovic in last year's New York finale, never lost serve in the contest.
He now goes on to face Uzbekistan's Denis Istomin, who logged a 6-3, 6-4, 2-6, 3-6, 6-1 winner over No. 20 seed Andreas Seppi Sunday.
Also posting third-round wins Sunday were fifth-seeded Czech Tomas Berdych, who sped past No. 31 Julien Benneteau of France 6-0, 6-3, 6-2, and No. 9 Swiss Stanislas Wawrinka, who overcame Marcos Baghdatis of Cyprus 6-3, 6-2, 6-7 (1-7), 7-6 (9-7).
Australian Lleyton Hewitt moved on as well, following up a Friday upset of sixth-seeded Juan Martin del Potro with a 6-3, 7-6 (7-5), 3-6, 6-1 defeat of Russian Evgeny Donskoy.
Waiting for him in the fourth round will be 20th-seeded Mikhail Youzhny of Russia, who bounced 12th-seeded Tommy Haas 6-3, 6-2, 2-6, 6-3.