After squandering a match point during the third set, Learner Tien was blitzed 6-1 in the fourth set by Daniil Medvedev. It looked as if the 19-year-old American - coming off a five-set win in round one - was cooked and seemingly being run over by a three-time Australian Open finalist.

At the age of 19, Learner Tien defeated Daniil Medvedev in a five-set thriller that finished just before 3 a.m. in Melbourne.

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).