Top seed Andre Agassi smashed Spain's Alex Corretja off the court for the loss of just five games on Tuesday to underline his credentials as U.S. Open favourite.
The American needed just 86 minutes to reach the second round 6-1, 6-2, 6-2, demolishing a player once ranked as high as two in the world.
"He knows how to win big matches so I just wanted to step up my game and make sure I executed well," Agassi, twice a champion and runner-up here last year said. "Today I got through it."
Less emphatic but equally successful was women's second seed Justine Henin-Hardenne.
The Belgian followed her compatriot and top seed Kim Clijsters, a winner on Monday , into the second round with a 7-5, 6-3 win over Hungary's Aniko Kapros.
Henin needed to dust off every weapon in her impressive armoury against the tennis equivalent of a brick wall before finally prevailing.
"I say the same thing, the first match at a Grand Slam is always tough," said the Belgian, who was beaten by Kapros in the opening round of the French Open last year.
"I knew it would be tough... that's a normal situation."
America's 1989 French Open champion Michael Chang bowed out, ending his career with a 6-3, 7-5, 5-7, 6-4 first round loss to Fernando Gonzalez in his 17th U.S. Open.
"New York means so much to me, playing here means so much to me," the 31-year-old said.
OVERCAME ILLNESS
Thai 11th seed Paradorn Srichaphan overcame illness to beat France's Cyril Saulnier 2-6, 6-2, 6-3, 7-6 with some powerful play.
"He was playing well and I was sick," Paradorn explained.
"I just had a problem breathing in the first set. It was a tough time and I had to ask the doctor for some medicine."
Kapros, while never likely to punch holes in the Belgian's game, ran and ran, chasing every ball and harrying her classy opponent in the opening match of the day.
The 129th ranked Kapros continually threw up lobs, scrambled groundstrokes back and confounded Roland Garros champion Henin's best efforts at clean winners throughout the 88 minute centre court contest.
The Hungarian's short, clubbed shots were a world away from the silken strokes of Henin, but for efficiency and determination she could not be faulted.
Ultimately those qualities were not enough and the Belgian world number three pulled away.
She will next face Croatian Silvia Talaja, who earlier ousted Madagascar's Dally Randriantefy 6-3, 6-0.
Yugoslav Jelena Dokic put in a solid performance to beat Swiss Emmanuelle Gagliardi 6-4, 6-2 while France's Mary Pierce was equally impressive in her 6-3, 6-2 win over German Stephanie Gehrlein.
Sixth seed Jennifer Capriati opens her account later on Tuesday with a match against Cristina Torrens-Valero.
In the men's draw, fourth seed Andy Roddick is due to meet Britain's Tim Henman in the night match at the $17.1 million Grand Slam.
