Federer wins first US Open game
The 17-time Grand Slam winner, 32, seemed untroubled by a previous back injury as he eased past the Slovenian in straight sets.
The Swiss dropped just one game on his serve during a comfortable victory at Flushing Meadows.
Seventh seed Federer could potentially meet Spanish second seed Rafael Nadal in the quarter-finals.
Argentina’s Maximo Gonzalez beat 14th seed Jerzy Janowicz in straight sets – 6-4 6-4 6-2 – on Court 13. The Pole, 22, who reached the semi-finals of Wimbledon earlier this year, struggled with a back injury that forced him to seek assistance from the trainer during the second set.
Grigor Dimitrov is also out after the 25th seed was beaten 3-6 6-3 6-4 5-7 6-2 by world number 95 Joao Sousa of Portugal.
The Bulgarian, 22, twice fought back from a break down to take the fourth set, but was unable to sustain the comeback in the fifth and final set.
Canadian 10th seed Milos Raonic beat Italy’s Thomas Fabbiano in straight sets 6-3 7-6 (8-6) 6-3 to set up a second round tie with Pablo Andujar of Spain. Andujar beat Thiemo de Bakker of the Netherlands 6-4 6-4 6-4 in their first round match.
The 13th seed, John Isner of the United States, hit 16 aces as he overwhelmed Italy’s Filippo Volandri 6-0, 6-2, 6-3.
In the women’s singles, sixth seed Caroline Wozniacki beat China’s Ying-Ying Duan 6-2 7-5. The former world number one, 23, won the first set in 35 minutes, but initially struggled in the second set and found herself 5-2 down.
The Dane, who was a finalist at Flushing Meadows in 2009 , then reeled off four games in a row before holding her serve to take the match.
Ana Ivanovic , the 2008 French Open champion, needed less than an hour to dispatch Anna Tatishvili of Georgia 6-2 6-0. The 25-year-old Serbian, who is seeded 13th in New York, took just 23 minutes to win the second set to love.
The 2011 Wimbledon champion and seventh seed Petra Kvitova of the Czech Republic beat Misaki Doi of Japan 6-2 3-6 6-1, while Russia’s Maria Kirilenko overcame Belgium’s Yanina Wickmayer 6-1 6-1 in just 59 minutes. (BBC)