Learner Tien proved one of the break-out stars of the season's first grand slam in Melbourne - and has continued his impressive progress by finishing off the Australian men's hopes at the Delray Beach Open in the US.
The 19-year-old Californian Tien provided one of the recent Australian Open's best stories when he outstayed three-time finalist Daniil Medvedev in the early hours to win an epic five-setter before going on to become the youngest man since Rafael Nadal to reach the fourth round.
