Later in 1778 Munro took Pondichéry from the French, but in 1780 in the Second Anglo-Mysore War the defeat of a British force by Hyder Ali at the Battle of Perambakam near Conjeeveram forced him to fall back on St. Thomas Mount. There, Sir Eyre Coote took command of the army, and in 1781 won a major victory against Hyder Ali at Porto Novo (Parangipettai), where Munro was in command of the right division. Negapatam was taken by Munro in November of the same year; and in 1782 he retired to Scotland.