Sara Tomic is through to the semifinals of the junior Australian Open after a tough fought 6-1, 5-7, 6-2.

Tomic, the sister of Australian world No.17 Bernard Tomic, battled stomach complaints as she advanced to the semifinal of the girls' championships.

If Sara can win the title, the Tomics will become the third Australian brother-sister duo to win the Australian Open junior singles championships.