German 17-year-old Justin Engel became the youngest player since Boris Becker 40 years ago to reach the quarterfinals of an ATP Tour grass-court tournament by making the last eight at the Stuttgart Open on Thursday.

Engel beat seventh-seeded Alex Michelsen of the United States 6-4, 6-4 to become the youngest quarterfinalist ever in Stuttgart. He is the youngest man to reach the quarters of any grass-court event since Becker won Wimbledon as a 17-year-old in 1985.