Osterley, under the command of Captain Samuel Rogers, left Portsmouth on 13 March 1781, bound for Bombay and China.

[1] Six days later, Osterley was present at the Battle of Porto Praya, when a French squadron under the Bailli de Suffren attacked Johnstone.

The French did capture the Indiamen Fortitude and Hinchinbrooke (recaptured the next day), and the victualer Edward, and gained a strategic victory, because Suffren beat Johnstone to the Cape and reinforced the Dutch garrison before continuing on his journey to the Ile de France (now Mauritius).

Still, Johnstone went on to capture five Dutch East Indiamen and destroy a sixth at the battle of Saldanha Bay on 21 July.

[1] the convoy left Johanna on 21 or 22 September, but ran into an adverse monsoon that drove the vessels to the coast of Arabia, and especially the four Indiamen Asia, Latham, Locko, and Osterley were driven further, to Kissen Bay, near the Bab-el-Mandeb.

[5] Osterley left Bombay on 8 August in company with the Indiamen Asia, Essex, and Locko, and the country ship Shah Byram Gore.

[d] As the squadron was sailing through the Strait of Malacca, on 9 September the ships encountered the 38-gun French frigate Pourvoyeuse, which was under the command of Captain de Lannuguy-Tromelin.

Homeward bound, she reached the Bocca Tigris on 4 January 1783 and St Helena on 18 June, and arrived at the Downs on 22 September.

She reached Madeira on 7 January 1785, Johanna on 30 April, Madras on 6 June, and Malacca on 31 July, and arrived at Whampoa on 1 September.

[8][f] On her return trip Osterley crossed the Second Bar on 18 February 1788, reached St Helena on 13 July, and arrived at the Downs on 23 September.

She sailed with a convoy of Indiamen that were bringing General Alured Clarke and his troops for the invasion of the Cape Colony.

Homeward bound, she crossed the Second Bar on 21 June, reached St Helena on 20 November, and arrived at the Downs on 9 February 1797.

A sharp action of about 45 minutes ensued in which Osterley sustained casualties of four men killed and 13 wounded before she struck.

After removing the stores he needed, Beaulieu-Leloup on 27 February permitted Piercy to proceed as a cartel for an exchange of prisoners.