(Beijing, October 13) The "Good Luck Beijing" 2007 International Badminton Invitational Tournament entered on its fourth day. In a semifinal match of the mixed doubles staged this morning world No. 1 Gao Ling/Zheng Bo beat fourth-seeded Zhao Tingting/Xu Chen 2-0 (21-12, 21-13) to march into the final first.