Nsofor goal keeps Nigeria hopes alive
The victory came after some frenetic attacking towards the end of their African zone Group B qualifier.
Nsofor's strike came after Obafemi Martins had his header saved. Martins had fluffed several earlier chances to give Nigeria the lead.
Tunisia, who started Sunday's penultimate set of qualifiers two points ahead in the standings, would have qualified for next year's finals in South Africa had second-placed Nigeria drawn.
They remain in command after Issam Jomaa's first minute goal sealed a 1-0 win at home to Kenya in Rades on Sunday.
Tunisia visit Mozambique while Nigeria travel to Kenya in the final round of group matches on Wednesday.