NEW YORK (Reuters) - Former champion Angelique Kerber cruised into the fourth round of the U.S. Open with a convincing 6-3 6-4 victory over 20-year-old American Ann Li at the Louis Armstrong Stadium on Friday.
Germany's Kerber, a three-times Grand Slam champion who won the title at Flushing Meadows in 2016, converted four break points and has yet to drop a set at the tournament while Li, ranked 128 in the world, was let down by 28 unforced errors.
The only real moment of concern for Kerber came late in the second set when she appeared to hurt her ankle chasing a wide shot, after which the 32-year-old walked gingerly between points.
But she held serve for a 5-4 lead and broke the American in the final game to move into the fourth round for the first time since her title win.
Li did, however, give a good account of herself, taking risks with some powerful forehand winners that caught the 17th seed Kerber off guard, but the 32-year-old German dictated play on the crucial points and was broken only once in the contest.
"She played pretty well," Kerber said. "It was really a tough forehand to return and she hits the ball really fast and with a lot of spin.
"I needed a little bit time to find my rhythm... because I had no idea what really to expect."
Kerber broke in the very first game of the match and then enticed Li into long rallies where the youngster showed glimpses of her booming forehand but had little else in her armoury.
Li, who finished the match with 36 winners to Kerber's 11, took risks but they proved her undoing as the American's frustration grew with every errant shot.
Kerber will next face another American, 28th seed Jennifer Brady, who beat France's Caroline Garcia, conqueror of top seed Karolina Pliskova in the previous round, 6-3 6-3.
(Reporting by Rohith Nair in Bengaluru; editing by Ken Ferris and Ian Chadband)