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

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

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

Alex de Minaur is bidding to reach his first Australian Open quarterfinal, however, talented Alex Michelsen isn't going to make his assignment easy.

Alex de Minaur overcame a one-set deficit and his own serving yips Saturday afternoon to defeat 31st-seed Francisco Cerundolo in a marathon third-round Australian Open match.

Alex de Minaur's Australian Open fourth-round opponent Alex Michelsen has a hip injury he received a medical timeout for in his previous match.