NEW YORK (AP) — If Novak Djokovic's shoulder was still bothering him, it didn't show.
Then again, he was barely around long enough to tell. He spent 44 minutes on the Arthur Ashe Stadium court Tuesday, taking a 6-0, 5-1 lead in his first-round match at the U.S. Open against Ireland's Conor Niland before Niland retired because of food poisoning.
It wasn't much of a test for the top-seeded Djokovic, who pulled out with an ailing shoulder while trailing in the second set of the Cincinnati Masters final on Aug. 21.
In his first match since, Djokovic won the first seven games, then after Niland won his single game, Djokovic tore off 16 points in a row before Niland retired. Djokovic moved to 58-2 on the year and this might have been the easiest of them all.
"Throughout the whole week I was carrying the pain and discomfort in my shoulder," Djokovic said. "After Cincinnati, I took some time off. I did everything to recover the shoulder. Today, I didn't feel any pain. I served well and I played well and I didn't have any concerns."
Djokovic would have been the overwhelming favorite regardless of Niland's health, though this match may have really been clinched Sunday night at dinner.
"We're thinking it was either salad or a pork dish," Niland said. "We're not giving away the name of the restaurant."
And so, a chance for this qualifier, ranked 197th, to see how he stacked up against the best in the world, turned into something much less. Did he learn anything from his 44 minutes on the stadium court?
"I was really wrapped up in myself today," Niland said. "I was simply trying to find any bit of energy I had. Focused on that. No chance to soak much in."
Djokovic, meanwhile, said he was glad to get a short match on an 80-degree day in New York — the first in what he hopes will be a seven-match run to the final. Already guaranteed one of the best tennis seasons in history, Djokovic is seeking his third major title of the year.
"The season's not over yet," he said. "I'm feeling really confident and fit and I want to have as much fun as I can."
Winning almost as easily Tuesday was the women's No. 1 seed, Caroline Wozniacki, who defeated Nuria Llagostera Vives of Spain, 6-3, 6-1.
Still in search of her first major title, Wozniacki is at the end of what some have viewed as a rough summer, losing her first match at both Toronto and Cincinnati — considered key leadups to the year's last Grand Slam. But last week, she won for the fourth straight year at New Haven, and she feels as if things are back on track.
"I know that everyone has to write their stories, but I think we should move on," she said. "Ask me about something else, something more interesting."
Elsewhere on the second day at the U.S. Open, No. 4 seed Victoria Azarenka defeated Johanna Larsson of Sweden 6-1, 6-3. She reached her first Grand Slam semi this year at Wimbledon and is another good candidate to win in a wide-open women's field.
"I always take it match by match," she said. "But I have been closer to my goals, so I can only look and stay positive and keep getting better."
No. 7 Francesca Schiavone, the 2010 French Open champion, overcame four double-faults in her last service game before pulling out a 6-3, 1-6, 6-4 win over Galina Voskoboeva.
Serena William, seeded 28th but always a big threat, had a night match Tuesday, as did defending men's champion Rafael Nadal.
In earlier men's action, Ernests Gulbis of Latvia upset 16th-seeded Mikhail Youzhny of Russia, who made a surprise trip to the semifinals last year before falling to Nadal.
Other winners included No. 5 David Ferrer, No. 11 Jo-Wilfried Tsonga, No. 17 Jurgen Melzer and American wild-card entry Donald Young.
No. 20 Yanina Wickmayer, No. 31 Kaia Kanepi and No. 11 Jelena Jankovic won on the women's side.