Former champion Angelique Kerber came through a fierce all-German tussle against Anna-Lena Friedsam 6-3 7-6 (8-6) to book her place in the third round of the US Open.
Angelique Kerber. Photo: PHOTOSPORT
Kerber, seeded 17th, was fast out of the blocks as she moved into a 3-0 lead but 109th-ranked Friedsam settled down and made her more illustrious compatriot work hard for victory.
Friedsam broke back but surrendered her own serve in the sixth game from 40-0 to allow 2016 winner Kerber to regain control with another break.
Kerber broke immediately at the start of the second set but again Friedsam refused to buckle and responded to break back when left-hander Kerber fired a forehand wide.
Friedsam, who suffered first-round exits on both her previous main draw appearances at Flushing Meadows, grew increasingly confident and worked tirelessly to force the left-hander into a tiebreak on Louis Armstrong Stadium.
Kerber drifted an attempted dropshot wide on her first match point at 6-5 but a wild forehand from Friedsam offered her another chance and she converted at the second attempt.
"It was really a tricky match and when you play against a German it's never easily mentally," Kerber, playing in her 50th grand slam tournament, said on court.
Kerber will face an American challenge next, either Alison Riske or Ann Li.
French Open finalist Marketa Vondrousova crashed out in the second round when Belarusian Aliaksandra Sasnovich beat the 12th seeded Czech 6-1 6-2.
Vondrousova endured a disappointing outing with her 16 winners overshadowed by 21 unforced errors as she became the highest seed in the women's field so far to be eliminated at Flushing Meadows.
Petra Kvitova overcame a bout of nerves and a rocky start to defeat Kateryna Kozlova 7-6 (7-3) 6-2 in her second-round clash.
Czech sixth seed Kvitova was off her game early on, committing 20 unforced errors during the first set - twice as many as her Ukrainian opponent - as she struggled with her serve.
The two-time Wimbledon champion committed a fifth double fault to hand Kozlova a break point and a 3-2 lead in the first set but recovered to save set point at 5-4 and eventually took the opener on a tiebreak.
-Reuters