Learner Tien, a 19-year-old qualifier from California, became the youngest American man to reach the Australian Open’s third round since Pete Sampras in 1990, upsetting Daniil Medvedev in five sets on Thursday.
Learner Tien, a 19-year-old qualifier from California, became the youngest American man to reach the Australian Open’s third round since Pete Sampras in 1990, upsetting Daniil Medvedev in five sets on Thursday.