Gernot Rohr’s men were almost assured of their place in Russia owing to their three-point lead and superior goals difference. Against the Chipolopolo they confirmed their place thanks to Iwobi's late impact.
In a keenly contested affair, Nigeria was forced to make an early change as Ogenyi Onazi was substituted owing to an injury.
The three-time Afrian champions defeated the Chipolopolo 2-1 away earlier in the group and they appeared set to do so again with few problems, Mweene making relatively straightforward saves from Moses Simon, Wilfried Ndidi and the lively Victor Moses.
Simon spurned an early chance to put Gernot Rohr’s men ahead as he stabbed wide from Victor Moses’ left-wing cross before Odion Ighalo forced Kenneth Mweene into a routine save at the other end.
Towards the end of the first half, Zambia’s glorious opportunity went begging with Alex Ng’onga at fault as he failed to convert with goalkeeper Ikechukwu Ezenwa to beat, firing wide from close range.
But there was no denying Nigeria in the 73rd minute as substitute Iwobi broke the deadlock with a calm finish from close range, firing home Abdullahi Shehu’s low pass.
Wedson Nyirenda’s men went in search of the equaliser as they refused to give up but their misses proved to be costly as their hopes of a win in Uyo faded in thin air.