US Open PHOTOS: Serena demolishes Schivaone

In one of the most one-sided matches seen on the Arthur Ashes centre court, Williams demolished Italy's Francesca Schiavone 6-0, 6-1 with an ominous display of precision and power.

The American showed no mercy against her opponent, who won the French Open in 2010 and was a finalist in Paris the following year, conceding just 23 points in the 60-minute romp.

"I'm really excited," she said in a courtside interview.

"I knew playing a former grand slam champion in the first round was a really tough draw so I decided to be super serious."

As the most fearsome player of her generation, the 31-year-old Williams has made a career out of destroying her rivals but has rarely been as impressive as she was on Monday.

With the New York crowd whooping and hollering in awe, Williams raced through the opening set in just 23 minutes, sealing it with a thunderous ace down the middle.

The World No 1 jumped out to a 4-0 lead in the second leaving Schiavone cursing in desperation. Exasperated, she turned and hugged a ball boy, eliciting sympathetic groans from the crowd but not a hint of pity from Williams.

The Italian did at least manage to avoid the dreaded 'double bagel' -- the ultimate humiliation for a tennis professional -- when she held serve in the fifth game.

But it was a just a temporary reprieve as Williams moved in for the kill, reeling off the next two games to seal a second round meeting with Galina Voskoboeva of Kazakhstan.

As a statement of intent, Williams could not have been any clearer about her ambitions at Flushing Meadows over the next two weeks.

Rafael Nadal made an ominous return to the US Open on Monday.

Roared on by the energetic New York crowds, Nadal turned on a masterclass of power hitting at Arthur Ashe Stadium.

Nadal, who missed last year's US Open because of a chronic knee problem, showed his intentions to make up for lost time as he demolished American wildcard Ryan Harrison 6-4, 6-2, 6-2.

Bouncing around the unforgiving Flushing Meadows hardcourt like a kangaroo, the Spaniard chalked up 28 winners despite the blustery conditions at the US National Tennis Center.

"For me, the chance to be back here playing is great," said Nadal. "The first match after two years in the Arthur Ashe is a great feeling."

Venus Williams rolled back the years to beat Belgium's Kirsten Flipkens in the first round as the final Grand Slam of the year burst into life.

Roared on by an energetic New York crowd on a blustery day at Flushing Meadows, Williams showed no signs of the back problems that have sidelined her for most of the year as she demolished her younger opponent 6-1, 6-2.

The 33-year-old American, the second oldest player in the women's singles draw, provided a glimpse of the form that saw her win the US Open in 2000 and 2001 as she romped to victory in just one hour and 24 minutes.

"It's good to be back," she said.

Williams has only played 18 matches this year and slipped to 60th place in the world rankings while Flipkens is enjoying the best season of her career.

The 27-year-old made the semi-finals at Wimbledon in July, her best result at any Grand Slam, and was seeded 12th for the US Open. Earlier this month, she beat Williams in Toronto after losing the first set 6-0.

"I was glad to close it out today," said Williams, whose younger sister Serena was scheduled to play her opening match on the center court later on Monday.

Flipkens was the first notable casualty in a wide open women's draw that promises to be one of the most competitive years.

China's Li Na, the 2011 French Open champion and runner-up in Australia this year, needed just 64 minutes to crush Olga Govortsova of Belarus 6-2, 6-2.

And Poland's Agnieszka Radwanska, the third seed, was even more ruthless, thumping Spain's Silvia Soler-Espinosa 6-1, 6-2 in 63 minutes in the opening match on the center court.

There was an early upset in the men's draw when Japan's Kei Nishikori, Asia's highest-ranked man, was beaten by British qualifier Dan Evans.

The Englishman, ranked 179th, stormed to a 6-4, 6-4, 6-2 win over the 11th seed to set up a second round meeting with combative Australian Bernard Tomic, who won a five-set slugfest with Spain's Albert Ramos.

"It's definitely a good one," said Evans, playing in his first US Open. "That was pretty good out there to play so well and against someone so highly ranked."