On March 25, 2006 she won the Women's World Chess Championship knock-out tournament in Ekaterinburg, Russia, defeating Russian IM Alisa Galliamova in the final 2½–½ (in a best-of-four match). The knockout event had 64 participants, with both former world champion Zhu Chen and reigning world champion Antoaneta Stefanova. Xu was three months pregnant at the time. She became China's 22nd Grandmaster by winning the event.