NEW YORK -- Roger Federer delivered another YouTube-worthy, between-the-legs shot at the U.S. Open.
The five-time champion at Flushing Meadows hit 18 aces in his 6-1, 6-4, 6-2 victory over 96th-ranked Brian Dabul of Argentina in the first round, part of Federer's remarkable 46-4 advantage in winners Monday night.
"There's nothing you can do when he has those days," Dabul said. "He's perfect."
No shot was more spectacular than the one Federer came up with while leading 5-3 in the second set.
He was at the net when Dabul sailed a lob high overhead. Federer turned and sprinted toward the baseline. A few steps from the wall behind the court in Arthur Ashe Stadium, and with his back to the net, Federer smacked the ball through his legs.
The shot cleared the net and landed in a corner for a winner beside Dabul, who raised his eyebrows and shrugged his shoulders.
"Only he can do that," Dabul would say later.
At the far end of the court, Federer celebrated the trick shot by raising his arms overhead and lifting his right index finger to signal No. 1. It was nearly identical to a back-to-the-court, through-the-legs passing winner Federer hit against Novak Djokovic in the 2009 U.S. Open semifinals.
"This one was incredible again," Federer said. "I turned around and couldn't believe the shot landed in the corner."
Asked if Monday's shot was better than the one against Djokovic, Federer said he'd need to go to the videotape to be sure.
"In terms of difficulty, maybe this one was harder, because I had the feeling I had to run a longer distance and I was further back somehow," he said. "I had to really give the last big push at the end. I didn't have time to set it up."
And it most definitely was real, no argument about that -- unlike the trick shot that has drawn more than 6 million views since being posted on YouTube two weeks ago. In that clip, shot in Zurich shortly after Wimbledon, Federer is seen serving a ball and swatting a metal bottle off a man's head -- twice in a row.
Federer has been coy about the authenticity of the video, and some have been skeptical, such as two-time major finalist Andy Murray, who said this weekend: "There's not a chance it's real."
Told that other players have wondered aloud about that one, Federer replied: "I can't tell you if it's real or not. That's up for debate. ... I'm not going to answer that question."
Could he hit a ball between his legs and knock a bottle off someone's head?
"That's kind of tough, the trajectory going up," Federer said with a grin, before acknowledging, "No, I wouldn't be able to do that."
OK, so there are limits to his brilliance with a racket in hand. Still, Monday's result made Federer 16-0 in U.S. Open night matches, and he declared afterward, "I feel very much at home here."
"Obviously, I have the experience to play under pressure and with so many people, high expectations, so I guess I can use that to my advantage," Federer said. "Then court speed, surroundings, the event and everything helps my cause to really do well and play well here. I always loved coming here. Never had a bad U.S. Open."
That perfect mark under the lights has helped Federer reach six consecutive U.S. Open finals; the only loss in that stretch was to Juan Martin del Potro a year ago.
"I'd like to go there again this year," Federer said. "The path is long and rough."
His streak of 23 consecutive Grand Slam semifinals ended with a quarterfinal loss to Robin Soderling at the French Open, and Federer lost again at that stage at Wimbledon.
But Monday's victory clinched a berth in the season-ending ATP World Tour Finals at London in November, which is for the top eight men.
If there was anything for Federer to lament about his performance against Dabul, it was this statistic: The 16-time major champion converted only five of 19 break points.
Federer had an explanation for that, though.
He recently began working with Pete Sampras' former coach, Paul Annacone, and Federer jokingly said: "Break-point conversion wasn't very good, so that's [Annacone's] mistake."
Andy Roddick, meanwhile, turned 28 on Monday, Day 1 of this year's U.S. Open, and after beating Stephane Robert of France 6-3, 6-2, 6-2, the ninth-seeded American was asked what significance he attributes to his age.
In typical Roddick fashion, he injected his reply with some humor.
"Obviously, I know I'm probably closer to the finish than I am to the start," he said. "But ... it's a number. I'm barely older than I was yesterday."
Well, yes, that's true. He also, however, is seven years older than he was when he won his lone Grand Slam title at the 2003 U.S. Open. There's a reminder of that accomplishment every time Roddick returns to Flushing Meadows: His spot in the locker room bears a special plate with his name and the year he was the champion, a bit of recognition he referred to as "the little deal on your locker that says you're special."
It's been an up-and-down year for Roddick, who recently discovered he had a mild case of mononucleosis. He was under doctor's orders to limit his physical activity, but he said he feels a lot better now than he did a month or so ago.
"It's going the right way," he said. "To be honest, once you decide to play, I think you throw all the excuses and everything else out the window. If I decide to play, then it's up to me to give 100 percent of what I have. So it's not something I really want to discuss too much from this point forward."
Two-time French Open runner-up Soderling also reached the second round by holding off a strong challenge from a qualifier who's 214th in the rankings.
The No. 5-seeded Swede hurt himself with 13 double-faults while edging Andreas Haider-Maurer of Austria 7-5, 6-3, 6-7 (2), 5-7, 6-4 Monday. Haider-Maurer hit 34 aces -- 26 more than Soderling.
The 23-year-old Haider-Maurer was making his Grand Slam debut and facing a top-10 opponent for the first time. Soderling appeared headed to an easy victory, taking the opening two sets and then holding four match points in the third.
But Haider-Maurer charged back, thanks mainly to his big serves, which reached up to 134 mph.
Mathieu beat the 32nd-seeded Australian 6-3, 6-4, 5-7, 4-6, 6-1. Mathieu had 72 winners and 65 unforced errors.
Mathieu, ranked 109th, was 4-8 at Flushing Meadows before Monday.
After Hewitt rallied from two sets down, Mathieu promptly broke his serve twice to go up 3-0 in the fifth set. Mathieu broke him again on Hewitt's 12th double-fault of the match to clinch the upset.
"I wasn't expecting a whole heap coming into this tournament, based on my preparation," said Hewitt, who had played only four matches, losing three, since Wimbledon.
Hewitt had never lost in the first round at the U.S. Open.
In other men's results Monday, Nikolay Davydenko, the No. 6 seed on the men's side, beat American Michael Russell 6-4, 6-1, 6-3. No. 11 Marin Cilic, No. 13 Jurgen Melzer and No. 22 Juan Carlos Ferrero also advanced. No. 27 Fernando Gonzalez of Chile retired against Ivan Dodig of Croatia.
Information from The Associated Press was used in this report.