 In 529, Erzhu Tianguang was one of the generals under the command of Erzhu Rong's close associate Yuan Tianmu (元天穆) when Yuan Tianmu attacked and defeated the rebel general Xing Gao (邢杲).At the same time, however, Yuan Hao the Prince of Beihai, who also claimed the throne, was attacking Luoyang with the support of rival Liang Dynasty, and Yuan Tianmu was unable to stop Yuan Hao.Emperor Xiaozhuang fled Luoyang, and Yuan Tianmu and Erzhu Tianguang also fled north with their troops, joining with Erzhu Rong.