key official Gao Jiong served as Yang Guang's assistant. In spring 589, the generals Han Qinhu () and Heruo Bi (), both under Yang Guang, crossed the Yangtze River and approached the Chen capital Jiankang. Soon, after Heruo defeated the Chen general Xiao Mohe, Jiankang fell, and the Chen emperor Chen Shubao was captured. Yang Guang, apparently fascinated by Chen Shubao's favorite concubine Consort Zhang Lihua, sent Gao Jiong's son Gao Dehong () to order Gao Jiong to hold Consort Zhang. Instead, Gao Jiong, comparing Consort Zhang to Daji (the wicked wife of King Zhou of Shang), beheaded her. Yang Guang thereafter resented Gao greatly, stating sarcastically, "It has been said, 'You should repay every good deed done to you.' I will repay Duke Gao later." By Yang Guang's orders, several of Chen Shubao's favorite officials, who were considered reasons for Chen's downfall, including Shi Wenqing (), Shen Keqing (), Yang Huilang (), Xu Xi (), and Ji Huijing (), were executed. It was said that the people praised Yang Guang for his actions. Chen Shubao and his own clan members, however, were treated with kindness, and at Yang Guang's request, Chen Shubao sent letters to Chen generals who had not yet surrendered to persuade them to do so, and they largely did. Later that year, Yang Guang's forces escorted them to the capital Chang'an. At the ceremony to present Chen Shubao to Emperor Wen, Yang Guang marched into the palace first, and Emperor Wen bestowed on Yang Guang decorated wagons, horses, clothing, and jade. Afterwards, Yang Jun was given the Yang Province (then moved to modern Yangzhou, Jiangsu) commandant post, and Yang Guang was returned to Bing Province. In 590, Emperor Wen swapped the defense posts of Yang Jun and Yang Guang, returning Yang Guang to Yang Province. In 594, Yang Guang urged Emperor Wen to offer sacrifices to Mount Tai—a traditional ceremony for emperors, but one that was rarely carried out. Emperor Wen rejected the elaborate traditional ceremonies, but did carry out a reduced ceremony at Mount Tai. In spring 600, with Ashina Dianjue, who had by now become Tujue's khan, attacking the borders, Emperor Wen sent Yang Guang, Yang Su the Duke of Yue, Yang Guang's brother Yang Liang the Prince of Han, and Shi Wansui () the Duke of Taiping, against Tujue, and they were largely successful against Ashina Dianjue, protecting the Qimin Khan Ashina Rangan,