The defending champions, who had suffered a shock 3-2 defeat to debutants Malawi in their opener, responded with a gritty performance at Al Madina Stadium to claim their first three points of the tournament.
Oshoala struck in the eighth minute, giving Nigeria the lead with a clinical finish. The Super Falcons were then reduced to 10 players in the 40th minute when defender Blessing Demehin was shown a red card.
Despite the numerical disadvantage, Justine Madugu’s side showed remarkable resilience and defensive discipline in the second half to keep Zambia’s dangerous attack, led by captain Barbra Banda, at bay.
The Copper Queens pushed hard for an equaliser but were unable to break down a resolute Nigerian defence. Nigeria created further chances on the counter while successfully limiting Zambia’s threat.
The result lifts the Super Falcons to three points in Group C, level with Zambia, who had earlier thrashed Egypt 6-0. Both teams remain in contention for a quarter-final place, with the final group matches still to come.
Nigeria will next face Egypt on Wednesday, 5 August, while Zambia take on Malawi. The Super Falcons’ ability to grind out a result while a player short marks a significant step in their title defence.