Victor Osimhen came to the tournament as an acclaimed goal-scorer, but it is his incredible workrate in searing heat which epitomises the Nigerian title challenge.
Concerns about the William Troost-Ekong-marshalled defence have proven unfounded with only one goal conceded.
Angola are one of the nations that have mocked the form book, winning three straight matches after never managing more than one win at a time in eight other appearances.
Gelson Dala is the joint second highest scorer with four goals and Mabululu has notched three ahead of a clash between the highest and lowest ranked survivors.
DR Congo coach Sebastien Desabre said before the tournament that his target was a quarter-finals spot for a country that won the tournament twice decades ago when known as Zaire.
While the Congolese upset record seven-time champions Egypt after a penalty shootout, Mohamed Bayo snatched an added-time winner for Guinea over Equatorial Guinea.