When Nguyễn navy reached Thị Nại Port, Bảo was ordered to fight against them.
Tây Sơn navy suffered from a double-pronged attack, Bảo was defeated by Tôn Thất Hội, Võ Tính, Nguyễn Huỳnh Đức and Nguyễn Văn Thành, and fled back to Quy Nhơn.
[1][2] Bảo was stripped of his position as Crown Prince, and granted the title Hiếu công (孝公, "Duke of filial piety") by his cousin Nguyễn Quang Toản.
Bảo was resentful, he colluded with Nguyễn Ánh, and planned to revolt against Tây Sơn dynasty.
In 1798, he revolted against Tây Sơn dynasty in Lê Trung's absence, and surrendered to Nguyễn lord.