Red-hot Rafael Nadal was an easy first-round winner on Day 1 at the 2013 U.S. Open.

The second-seeded former world No. 1 star whipped struggling American Ryan Harrison, 6-4, 6-2, 6-2, in 2 hours, 6 minutes at Arthur Ashe Stadium on the grounds at the USTA Billie Jean King National Tennis Center.

Nadal captured his lone U.S. Open title in 2010 and was the runner-up in 2011. He missed last year's Open because of a knee injury.

The 27-year-old Spanish great is now 16-0 on hardcourts this year, including recent back-to-back Masters titles in Montreal and Cincinnati.

Nadal is the reigning French Open champ who suffered a shocking opening- round loss against unheralded Belgian Steve Darcis at Wimbledon back in June.

David Ferrer, June's French Open runner-up to Nadal, also coasted Monday, as the fourth-seeded Spaniard downed Australian Nick Kyrgios, 7-5, 6-3, 6-2.

Seventeen-time Grand Slam champion and former world No. 1 Roger Federer, a five-time U.S. Open champion, was also supposed to be in action Monday, but rain halted the night session and pushed his match against Grega Zemlja to Tuesday.

Vasek Pospisil and Santiago Giraldo were also leading in the fourth set of their matches before play was stopped.

Meanwhile, eighth-seeded nifty Frenchman Richard Gasquet drubbed American journeyman Michael Russell, 6-3, 6-4, 6-2.

A substantial Day-1 upset came when British qualifier Daniel Evans stunned 11th-seeded Japanese Kei Nishikori, 6-4, 6-4, 6-2, in 1 hour, 57 minutes. Nishikori, a third-round loser in New York a year ago, titled in the United States, in Memphis, back in February.

Two other seeded players was ousted Monday, as 27th-seeded Fernando Verdasco of Spain and No. 30 Ernests Gulbis of Latvia were each shown the door in five- set marathons. Croat Ivan Dodig got the best of Verdasco, 6-3, 7-5, 1-6, 4-6, 6-3, while Austria's Andreas Haider-Maurer advanced through Gulbis with a 3-6, 6-3, 1-6, 7-6 (7-4), 6-4 comeback victory.

In other action involving seeds, No. 18 Serb Janko Tipsarevic got past Uruguay's Pablo Cuevas 6-3, 6-7 (5-7), 6-3, retired, 19th-seeded Tommy Robredo of Spain sent home Australia's Marinko Matosevic, 6-3, 6-7 (6-8), 6-3, 6-2, No. 23 Spaniard Feliciano Lopez overcame Frenchman Florent Serra 6-7 (4-7), 6-2, 6-3, 6-3, and No. 32 Russian Dmitry Tursunov beat Slovenian Aljaz Bedene 7-5, 4-6, 6-3, 6-0.

Also, American Bradley Klahn snuck past Frenchman Kenny De Schepper 6-7 (5-7), 6-2, 7-6 (7-0), 7-6 (7-4), former world No. 3 Russian Nikolay Davydenko outlasted American Rhyne Williams 6-3, 4-6, 1-6, 7-5, 6-0, and capable Aussie Bernard Tomic snuck past Spaniard Albert Ramos 6-3, 3-6, 4-6, 7-6 (7-1), 6-3.

Other first-round winners include: Mikhail Kukushkin, Roberto Bautista, Dudi Sela, Stephane Robert, Guillaume Rufin and Frank Dancevic.