 Later that year, Xue was made deputy to the general Cheng Mingzhen () in an operation against Goguryeo, and they captured Goguryeo's city Chifeng (, in modern Fushun, Liaoning) and defeated the Goguryeo general Du Bangnu ().In 659, Xue personally led a surprise cavalry charge to attack the Goguryeo formation under the command of Goguryeo general Wen Shamen () and defeated him, single-handedly killing dozens of enemy soldiers in the battle.He also engaged Qidan forces, capturing their chief Abugu () and taking him back to the eastern capital Luoyang.