NEW YORK (AFP) - Roger Federer made a solid start to his bid for an 18th Grand Slam title, advancing to the second round of the US Open by defeating Slovenia's Grega Zemlja 6-3, 6-2, 7-5 on Tuesday.
The 32-year-old Swiss star, who as the seventh seed is at his lowest spot in the US Open since 2002, won a match postponed by rain from Monday night to book a last-64 meeting with Argentina's Carlos Berlocq.
"I felt great," Federer said. "Day sesion or night session it doesn't really matter when you play on Arthur Ashe Court."
Federer, whose 56th Grand Slam start in a row matched Wayne Ferreira for the all-time record run, has only one title in his past 14 Slam starts, that coming last year at Wimbledon.
After a second-round exit at Wimbledon, his earliest Grand Slam ouster since winning his first Slam title in 2003 at the All England Club, Federer needed only 93 minutes to eliminate Zemlja despite surrendering a third-set break.
"You're going to have some hiccups like I had today. It was a minor one," Federer said. "I might have had more confidence if I had closed it out without that. This way I had to fight a bit more. Who knows? Maybe that gives me confidence too."
Federer, who won five US Open titles in a row from 2004-2008, has not made the championship match on the Flushing Meadows hardcourts since losing to Juan Martin Del Potro in the 2009 final.
This year, Federer is on a quarter-final collision course with second seed Rafael Nadal, whom he has never faced at the US Open.
World number one Novak Djokovic, a six-time Grand Slam champion who captured his fourth Australian Open crown in January, launches his quest for a fourth consecutive US Open final later when he faces Lithuanian Ricardas Berankis.
Also starting later will be two-time Australian Open winner Victoria Azarenka, who faces German Dinah Pfizenmaier. The second seed from Belarus lost to world number one Serena Williams in last year's US Open final.
Canadian 10th seed Milos Raonic fired 28 aces in beating Italy's Thomas Fabbiano 6-3, 7-6 (8/6), 6-3, while fellow big server John Isner blasted 16 aces to down Italy's Filippo Volandri 6-0, 6-2, 6-3.
Raonic, 22, is confident he can reach his first Slam quarter-final from a section of the draw that features Spanish fourth seed David Ferrer and French eighth seed Richard Gasquet.
"I think I can put myself in that position," Raonic said. "I just have to make the opportunities and convert them. If I play well, I can get very close if not do it. I think I can get much better."
Two other 22-year-olds in the top 25 were ousted. Argentine qualifier Maximo Gonzalez upset Polish 14th seed Jerzy Janowicz 6-4, 6-4, 6-2 as the Wimbledon semi-finalist struggled with back pain and Bulgarian 25th seed Grigor Dimitrov, Russian star Maria Sharapova's boyfriend, lost to Portugal's Joao Sousa 3-6, 6-3, 6-4, 5-7, 6-2.
Czech seventh seed Petra Kvitova, the 2011 Wimbledon winner, and 2009 US Open runner-up Caroline Wozniacki withstood challenges from tenacious Asian rivals to advance.
Kvitova, the top-ranked rival in Azarenka's quarter of the draw, fought off Japan's 92nd-ranked Misaki Doi 6-2, 3-6, 6-1 while Danish sixth seed Wozniacki dispatched 133rd-ranked Chinese qualifier Duan Ying-Ying 6-2, 7-5.
Duan made 46 unforced errors but kept pressure on Wozniacki, who battled to avoid a repeat of last year's US Open first round ouster while boyfriend Rory McIlroy, a two-time major golf champion, watched from the stands.
"She got a little tight at the end and I got a bit lucky as well," Wozniacki said. "I just kept my focus and kept fighting for every point. It was a day of survival. It was not about being pretty. It was about getting the job done."
Doi, a 22-year-old left-hander whose only prior US Open appearance ended in a 2011 first-round cramping retirement, tested Kvitova in breezy conditions.
"I didn't play my game all the match," Kvitova said. "I didn't have focus. I have to have more confidence."
The US Open is the only Grand Slam event where Kvitova, who next plays Serb Bojana Jovanovski, has not reached the semi-finals.
"I like Wimbledon, which is very calm," Kvitova said. "Here it's more crowd and big show. I like matches on the big stadium too but the people are everywhere. It's too much crowd."
Serb 13th seed Ana Ivanovic, the 2008 French Open winner, beat Georgian Anna Tatishvili 6-2, 6-0 in 58 minutes. She faces Romanian Alexandra Dulgheru next.