Nigeria inched closer to a sixth Fifa World Cup berth after traveling to draw 1-1 with Cameroon in Yaoundé on Monday.
Moses Simon put the Super Eagles in front just on the half-hour mark, leaving the Indomitable Lions to fight back in front of their home fans at Stade Ahmadou Ahidjo.
Simon scored with a close-range shot past goalkeeper Fabrice Ondoa after a low cross eluded several Cameroon defenders.
But striker Vincent Aboubakar, after coming off the bench in the second half, drew level via a penalty with 15 minutes of regulation time to play.
A collision between Arnaud Djoum and Nigeria goalkeeper Ikechukwu Ezenwa led to the spot-kick, and Aboubakar scored with a shot into the middle of the net.
Having been thrashed 4-0 by the Super Eagles on the weekend, the stalemate provides at least some redemption for the Indomitable Lions, though their hopes of reaching Russia 2018 are all but gone.
The result does mean that Nigeria will have to wait until at least the next round of matches in October to confirm their place at the World Cup finals.
The unbeaten leaders now have 10 points from four matches in Group B and a home win over Zambia on October 7 will clinch a ticket to the Russia tournament.
Cameroon: Ondoa, Fai, Teikeu, Banana, Leuko, Zambo Anguissa, Djoum, Siani, Moukandjo/62’ Bassogog, Olinga/81’ Ngamaleu, Nsame/62’ Aboubakar
Nigeria: Ezenwa, Shehu, Balogun, Troost-Ekong, Echiejile, Onazi/87’ Etebo, Ndidi, Mikel/65’ Agu, Simon, Moses, Ighalo/80’ Iheanacho