In November 1839, Hall obtained command of "Nemesis" of the British East India Company in China, where he served in the First Anglo-Chinese War (1839–42). For his services, the Admiralty procured an Order in Council to enable it to make him a lieutenant on 8 January 1841. The Admiralty later obtained power to enable him to count his time in the "Nemesis" as if he had served in one of Her Majesty's Ships. The ship's first engagement was against Chinese forts and a fleet of junks in the Second Battle of Chuenpi on 7 January 1841. He was Mentioned in Despatches for his part in the battle. He later fought in the Battle of First Bar on 27 February, and the Broadway expedition on 13–15 March. In commemoration of his service, he was commonly known in the navy as "Nemesis Hall". William Dallas Bernard, an Oxford graduate who studied life and customs in China, used Hall's notes to write an account of the war in the "Narrative of the Voyages and Services of the Nemesis from 1840 to 1843" (1844). Under the command of Richard Collinson, then Lieutenant Hall also saw action on the island of Taisam near Ningbo in February 1842 on the "Nemesis". He was promoted captain with seniority on 22 October 1842.