In Wellington City, thefifth seed Thien, 16, dropped in the first set before recovering to win3-6, 7-5, 6-0. He faces another Australian, the third-seeded JackSchipanski, in the semi-final match on Feb. 11.
Earlier, Thiendefeated New Zealand's Pratt Keerasuntonpong 6-3, 6-3 in the first roundand Brafley Mousley of Australia 6-3, 6-1 in the next round beforeeliminating local Cameron Norrie 6-1, 7-6 in the third.
The six-day tournament is scheduled to finish on Feb. 12 in Wellington.
Thienwas ranked 241 in the world according to the latest world ranking tablereleased on Feb. 7 by the International Tennis Federation. He attendedtraining courses in the US in 2005, just two years after he took up thesport at the age of eight./.