There are three American men aged 23 and under in the second week of a Grand Slam. That hasn't happened since 2003

Two friends from California, Learner Tien and Alex Michelsen, have both reached the fourth round at the Australian Open

Two of four American men still playing in Melbourne, Irvine native Tien, 19, and Aliso Viejo native Michelsen, 20, became friends on the youth tennis circuit