The next year, in 1788, Võ Tánh decided to join Nguyễn Ánh's side and integrated his entire army into the Nguyễn army.
In 1789, Tánh forced the Tây Sơn general Pham Van Tham, who was the general-in-chief of the Tây Sơn garrison in southern Vietnam, to surrender to the Nguyễn army, which marked the end of Tây Sơn rule in Gia Định.