Russia's number-five seeded Daniil Medvedev lost to the 19-year-old, 121st ranked American Learner Tien 3:6, 6:7 (4-7), 7:6 (10-8), 6:1, 6:7 (7-10) in a Grand Slam tennis tournament 2nd round match at the Australian Open that lasted almost five hours.more