Coco Gauff remains on semi-final collision course with defending champion Aryna Sabalenka but she dropped her first set of the year at the Australian Open overnight. The world No.1 Sabalenka also refused to back a tennis legend's criticism of scheduling of women's matches.

Learner Tien pulled off a massive upset against Daniil Medvedev at the Australian Open. So, who is Tien, the 19-year-old out of California?

The Irvine native and 19-year-old qualifier, who played one semester at USC, wins a 4-hour, 49-minute thriller that ends at nearly 3 a.m. in Melbourne