Roger Federer served notice he was still a powerhouse at the US Open and punctuated his performance with another sensational shot for the ages in a first-round rout over Argentine Brian Dabul Monday.

Federer, whose run of five successive US titles was snapped last year in a five-set final against Argentine Juan Martin Del Potro, closed the opening day's action with a 6-1, 6-4, 6-2 victory on Arthur Ashe center court.

Federer blasted 18 aces to none for Dabul and cranked out 46 winners to his opponent's four.

"I've never lost night sessions. I feel very much at home here," said the 29-year-old Federer. "I always come out and played some good tennis here over the years. I've been in six straight finals."

Photographs: Reuters

Federer turned master showman when he reprised the between-the-legs winner he hit last year in the semi-finals against Serbia's Novak Djokovic with an equally spectacular between-the-legs winner that left Dabul stunned on the other side of the net late in the second set.

Federer threw his arms up in triumph while cheers rained down and fans showed their adulation by bowing to the 16-time major champion while Dabul applauded with his racket.

"I've only hit a few in my life and two on center court in night session play here in New York," the second-seeded Federer said in an on-court interview. "It's amazing to share this moment with you guys. Thanks for the ovation and I love it."

Federer raced back to retrieve a lob from left-hander Dabul and with his back to his opponent, stretched to reach it from well beyond the baseline and uncorked a rifle shot through his legs that rocketed deep into the backhand corner leaving the Argentine frozen in stunned appreciation.

Defending champion Kim Clijsters of Belgium overcame a second-set scare to defeat Greta Arn of Hungary 6-0, 7-5 in the first round.

Clijsters sailed through an 18-minute opening set on a sun-kissed Arthur Ashe center court but fell behind 4-0 in the second set before roaring back to seize command.

The second-seeded Belgian ran off 12 straight points to pull within 4-3 and then broke in the 10th game and again in the last game to close out the match.

"I was just excited to go out there," Clijsters said about getting her title defense under way. "I'm happy with the way I served. That's been a stroke that I've been paying a lot more attention to during my practicing the past few weeks."

Sania Mirza booked her place in the second round with a comprehensive win over Michelle Larcher de Brito of Portugal.

The Indian, who had to play three qualifying round matches to get into the main draw, won 6-3, 6 2.

Sania, whose best ever major showing came at the US Open in 2005 when she made it to the fourth round, is coming off a long injury lay-off.

The 23-year-old made it to the final of an ITF event in Vancouver in her preparation for the Open.

She beat Catalina Castano of Colombia in the final round of the qualifying to book her berth in the season's final major.

Martina Navratilova returned to the scene of some of her most notorious on-court battles at Flushing Meadows for the opening ceremony of the US Open on Monday.

But it was the four-time US Open champion's battle off the court with breast cancer which took centre stage at Arthur Ashe Stadium on a night in which organisers celebrated "those who dream, succeed and inspire."

The 53-year-old, one of the greats of women's tennis, has led a very public fight since being diagnosed with non-invasive breast cancer early this year.

"It's the positive attitude that gets you through life and it is a choice," she said after being the focal point of the opening night celebrations in New York.

"I've always been too much of an optimist where I sort of ignore bad stuff until it sits right there in front of me. I'm saying nothing is going to go wrong and, when it does, that's when I deal with it. That's how I've gotten through life. I think it's done me pretty well."

Andy Roddick celebrated his 28th birthday by romping past France's Stephane Robert 6-3, 6-2, 6-2 in his first-round match.

Ninth-seeded Roddick, the 2003 US Open winner, made an emphatic start on a hot, sunny day despite struggling with an energy-sapping illness this season.

The top-ranked American finished the 102-minute match in familiar fashion, when his sizzling serve on his first match point was returned long by the 30-year-old French journeyman, playing for the first time on Arthur Ashe center court.

"I was happy." Roddick told the Arthur Ashe center court crowd about his form and brisk victory. "Conditions are a little tricky out there. The wind blows a little out there."

Venus Williams showed some effects of a troublesome knee but displayed enough of her trademark power to beat Italian Roberta Vinci 6-4, 6-1 in the opening night match of the US Open.

Twice former champion Williams winced after landing on her left leg while striking a swinging forehand volley in the first set but the third-seeded American battled on in her first match since Wimbledon.

"I landed on that leg on the swing volley," Williams said in an on-court interview, but gave credit to the 65th-ranked Vinci for putting up a good fight and clawing back from 3-0 to tie the first set 4-4.

"I was playing against a tough opponent today. She hits that slice so well. She didn't make a lot of errors ... so I was really happy to get through after not playing in forever."

Frenchman Paul-Henri Mathieu handed former world number one Lleyton Hewitt his earliest ever exit from the US Open with a battling 6-3, 6-4, 5-7, 4-6, 6-1 in the first round.

The Australian, champion at Flushing Meadows in 2001 and seeded 32nd, showed typical grit to fight back from two sets down but Mathieu gathered himself to win the decider and clinch victory after three hours 39 minutes.

Hewitt, who had a second bout of hip surgery in January, looked down and out when Mathieu won the first two sets with a sparkling array of winners but the Australian hit back as the Frenchman's nerve faltered.

But Mathieu, who has dropped from a career-high ranking of 12 to 109 after a series of injuries, broke serve three times in the fifth set to clinch a dramatic victory.