"sans pareil" was commissioned at plymouth on 12 november 1852, under the command of sydney dacres. she was initially at lisbon, but by 1853 was serving with the channel fleet. the outbreak of the crimean war led to her being reassigned to the black sea. on 14 november 1854 she was driven ashore at balaklava, russia. on 22 november, "sans pareil" came under the command of acting captain leopold heath. he commanded her until february 1855, when captain woodford john williams took over. in september 1855 "sans pareil" was used to transport mortars to the baltic. captain astley cooper key took over on 9 january 1856, and was placed in charge of a division of gunboats. after the end of the war "sans pareil" was used to return troops from the crimea, and by march 1857, had been sent to the far east. key and the "sans pareil" were present in china during the second opium war, with key commanding the naval brigade at the capture of canton on 28 december 1857. key was invalided back to britain in april, and was replaced by . he was in turn replaced by captain rochfort maguire, who remained in command until her return to plymouth at the end of 1859.