NEW YORK (AP) Angelique Kerber has rolled into the U.S. Open quarterfinals for her best run at a Grand Slam tournament.
The 92nd-ranked German beat Monica Niculescu of Romania 6-4, 6-3 Sunday in a matchup of unseeded players. Niculescu is ranked 68th and also was also playing in the fourth round of a major tournament for the first time.
Kerber upset 12th-seeded Agnieszka Radwanska in the second round. Niculescu beat 27th-seeded Lucie Safarova in the third.
The 23-year-old Kerber will likely earn a career-best ranking with her quarterfinal appearance. She's never been above No. 45. Kerber is one of three German women in the fourth round, the first time that's happened at the Open since 1987.