Learner Tien, a 19-year-old from California, stunned fifth-seeded Daniil Medvedev in five sets to reach the Australian Open's third round. Tien is now the youngest American man to reach this stage since Pete Sampras in 1990, showcasing remarkable composure and determination in a match that lasted nearly five hours. Medvedev's defeat marks his earliest exit from the tournament in several years, while Tien looks forward to facing Corentin Moutet in the next round.