It resulted in the failure of the Chinese to restore the last Lê emperor Chiêu Thống, who had been usurped by the Tây Sơn.

After learning about the actions of Chỉnh, an army under Vũ Văn Nhậm was sent by Huệ to attack Thăng Long.

According to the Draft History of Qing, a navy had been dispatched from Qinzhou to attack Hải Dương, which, however is not mentioned in Vietnamese records.

[15] Boisserand, a French missionary, in a letter to MEP on 14 March 1789, claimed that the Chinese army was roughly 36,000 men.

The Chinese swiftly pushed further towards the south, threatening the unprepared Tây Sơn army, which dispersed in all directions.

Nguyễn Văn Hòa (阮文和) rallied the remnants of the army and occupied Tam Giang, Yên Phong District to confront the Chinese.

Having assessed the situation Ngô Văn Sở ordered Lê Duy Cận to write a letter to Sun Shiyi.

[19] On November 24 (December 21, 1788), Sun Shiyi installed Lê Chiêu Thống as "king of Annam" in Thăng Long.

Lê Chiêu Thống increasingly disappointed his supporters as he reportedly was narrow-minded and exceptionally cruel, who had cut off the legs of his three uncles, whom had surrendered to Tây Sơn army before.

After the coronation he marched north with about 20,000 soldiers, recruited volunteers while in the Nghệ An Province thereby increasing his force to 100,000 troops.

A navy led by Nguyễn Văn Tuyết sailed from Lục Đầu River to attack the Lê supporters in Hải Dương.

Another navy led by Nguyễn Văn Lộc, sailed from the Lục Đầu River to attack Phượng Nhãn and Lạng Giang.

A cavalry contingent (including war elephants) led by Đặng Tiến Đông, marched to attack Cen Yidong in Đống Đa; another cavalry (including war elephants) led by Nguyễn Tăng Long marched past Sơn Tây to attack Xu Shiheng in Ngọc Hồi (a place near the Thanh Trì).

The Tay Son had surrounded the city, bringing heavy cannons on the back of elephants and breached its forts.

The Qing generals Xu Shiheng, Shang Weisheng, Zhang Chaolong and Cen Yidong were killed in action.

Countless Qing soldiers and supporters drowned while crossing the river, including general Li Hualong.

[12][13] Because of his rapid victory over the Qing interventionists, Nguyễn Huệ was nicknamed by some contemporary missionaries as "new Attila" or "new Alexander.

According to the Khâm định Việt sử Thông giám cương mục, Sun comforted Lê Chiêu Thống and promised that he would gather new troops and reinstall him.

[23] For the Qianlong Emperor, the motivation for accepting the arrangement was to retain the Qing's supremacy and stabilize their southern border.

[23] Chinese and Vietnamese sources agreed that Nguyễn Huệ sent an imposter with a delegation to Beijing, where they were received with lavish imperial favors.

[23] The Qianlong Emperor approved the proposal and bestowed Nguyễn with the title An Nam quốc vương ("King of Annam").

[23] Nguyễn Huệ was resentful, trained his army, built large warships and waited for an opportunity to take revenge on Qing dynasty.

Infamous Chinese pirates, such as Chen Tien-pao (陳添保), Mo Kuan-fu (莫觀扶), Liang Wen-keng (梁文庚), Fan Wen-tsai (樊文才), Cheng Chi (鄭七) and Cheng I (鄭一) were granted official positions and/or noble ranks under the Tây Sơn empire.

Recorded as a military victory so severe, it has been speculated, that the event might have prevented the Qing from other attempts to invade Southeast Asia.