Federer is trying to win a third successive US Open title

Nadal opened play on Arthur Ashe Stadium and overcame Mark Philippoussis in straight sets, 6-4 6-4 6-4.

Federer was third on the main court and had an even more comprehensive win over Yeu-Tzuoo Wang, thrashing the Taipei player 6-4 6-1 6-0.

Ninth seed Andy Roddick joined the top two in the second round with a 6-3 7-6 6-3 win over Dane Kristian Pless.

Former champions Lleyton Hewitt and Marat Safin earlier went through, along with fourth seed David Nalbandian.

Australian Hewitt, seeded 15, beat Albert Montanes 7-5 6-4 6-3, while the unseeded Safin saw off Robin Vik of the Czech Republic 6-1 6-1 3-6 6-3.

"For me this is where it started on the Grand Slam level," said 2001 champion Hewitt.

He served unbelievable, especially the first serve Nadal on Philippoussis

"It seems I play well at tournaments that I have had good memories of in the past

Out on Court 11, Nalbandian battled back from two sets down to beat Michael Berrer of Germany.

The Argentine looked to be heading for an early exit when Berrer raced through the second set tie-break, but Nalbandian came through 4-6 6-7 (2-7) 6-3 7-5 6-2 and faces Safin next.

Tenth seed Fernando Gonzalez, who could face Andy Murray in the third round, beat Jiri Vanek 6-2 6-3 6-2.

Former world number three Guillermo Coria retired with a torn thigh muscle when losing 2-3 in the first set to American wildcard Ryan Sweeting.

Philippoussis hammered 19 aces against Nadal but also made 35 unforced errors.

"He served unbelievable, especially the first serve," said the Spaniard. "Sometimes three aces in a game, two aces.

"Mark was playing good. He had a very good forehand, too. I played a very good match. If I was playing a bad match, I was losing."

Federer had little trouble with Wang and was naturally pleased with his form.