After his exploits at the 1991 FIFA U-17 World Championship, 15-year-old Duah was bought by Serie A club Torino FC, alongside teammates Mark Edusei, Mohammed Gargo and Samuel Kuffour.
After two years in Turkey with as many clubs, Duah joined RCD Mallorca in the Spanish second division, being sparingly used as the Balearic Islands side promoted to La Liga.
Duah was used regularly by Leiria in the following Primeira Liga campaigns, but only appeared in ten matches in 2001–02 (three goals) as the José Mourinho-led team qualified to the UEFA Intertoto Cup after finishing seventh.
Duah closed out his career in 2008 at nearly 32, after two-year spells in Lebanon and Israel with Nejmeh and Hapoel Acre, respectively.
Duah was a member of Ghana's under-17 team that won the 1991 FIFA World Championship in Italy, scoring his only goal in the tournament in the final against Spain (1–0).