Reigning world U17 champions Nigeria rallied in the second half, hitting the wood-work twice and drawing at least two good saves from South African goalkeeper Mondli Mpoto.
But the Amajimbos held on to reach their first final at this junior level. Reeve Peter Frosler was in excellent form at the back and combining well with skipper Keanu Gregory, kept the menacing eaglets at bay throughout the match. In moments when the eaglets breached the backline, goalie Mpoto was in superb form, thwarting everything Nigeria threw at him.
It was the first match the eaglets failed to score at the 2015 championships having come from the group stages with two victories over Niger and Zambia, 2-0 and 3-1 respectively and a one all draw against Guinea.
South Africa came off the group stages with identical 2-2 draws against Cote d'Ivoire and Mali and a 3-1 win over Cameroon.
Amajimbos now await the winner of Thursday's semi-final between Mali and Guinea to complete the equation for Sunday's final to be contested at the Seyni Kountche.