Betting Australian Open: Learner Tien, a 19-year-old from Irvine, California, won the first two sets of his second-round match with fifth-seeded and former world #1 Daniil Medvedev. The qualifier almost saw that lead turn into an epic collapse, as his 6-3, 7-6(4) performance in the first two sets was followed by a 6-7(8) loss in the third set and then a 1-6 debacle in the fourth.