The first two times Roger Federer and Grega Zemlja met, the Swiss superstar smoked the Slovenian. Tuesday's result was predictably similar.
The seventh-seeded Federer defeated Zemlja in straight sets, 6-3, 6-2, 7-5.
The two traded games to start the match before Federer took three straight games to take the first set. Federer broke Zemlja to open the second set, which he easily won. Zemlja pushed back in the third, but couldn't take the set despite breaking Federer's serve for the first time in the match.
The five-time US Open champion is trying to round back into form after battling a back issue that has hindered his game, dropping the former world No. 1 to seventh, his lowest ranking since 2002. He was noticeably sharper Tuesday, handling Zemlja from the outset.
Federer moves on to face Argentinian Carlos Berlocq in the second round.
No trouble for Azarenka
Victoria Azarenka began her quest to return to the US Open final by blanking Dinah Pfizemaier, 6-0, 6-0 Tuesday night.
It took the No. 2 seed a little over an hour to dispatch of Pfizemaier, who hardly helped her cause with 26 unforced errors.
Azarenka, who lost in last year's final to Serena Williams, moves on to face Aleksandra Wozniak in the second round.
Djokovic barely breaks a sweat
Top-seed Novak Djokovic had no trouble with Ricardas Berankis, winning 6-1, 6-2, 6-2.
Djokovic dealt 10 aces, while Berankis stumbled to 28 unforced errors -- a recipe for disaster for the Lithuanian.
"I love the night session, it's very exciting," Djokovic told ESPN after the match. "I'm very happy with the performance overall."
The world No. 1 will face Benjamin Becker in the second round.