American teenager Learner Tien stuns Daniil Medvedev in nearly 3 a.m. finish at the Australian Open Posted on January 17, 2025 by Sport News Now American teenager Learner Tien produced arguably the biggest shock of the Australian Open so far as he defeated last year’s runner-up Daniil Medvedev in five sets, 6-3, 7-6 (4), 6-7 (8), 1-6, 7-6 (7).