Learner Tien stages Australian Open upset of No. 5 Daniil Medvedev. Who is the American teenager?
Learner Tien defeated No. 5 Daniil Medvedev in a fifth set tiebreaker that ended early Friday morning. |!| Torrington
Learner Tien defeated No. 5 Daniil Medvedev in a fifth set tiebreaker that ended early Friday morning. |!| Torrington