New York - Second-seeded German Angelique Kerber made a definitive start to her US Open campaign on Monday, reaching the second round when Polona Hercog retired without winning a game.
Kerber, who toppled Serena Williams to lift the Australian Open crown in January and fell to the American in the Wimbledon final, was leading 6-0, 1-0 when 120th-ranked Hercog of Slovenia called it quits in the sultry heat of Flushing Meadows' Arthur Ashe stadium court.
Kerber, who could topple Williams from atop the world rankings in the final Grand Slam of the season, next faces either France's Alize Cornet or Croatian Mirjana Lucic-Baroni.