Cape Town - Amajita were beaten 1-0 by Senegal in Wednesday evening's CAF U20 Africa Cup of Nations clash at the Stade General Seyni Kountche in Niamey.
Coach Thabo Senong's men were under pressure in the early stages as the Senegalese threw bodies forward into attack.
The South Africans grew into the game and started to get their passing game going with measured build-ups from the back, though they struggled to create openings.
Goalkeeper Khulekani Khubeka made his first save soon after from Souleymane Aw's free-kick just before the break.
After the interval the action remained tight and Senong decided to change things up as he brought off Kobamelo Kodisang for Nkosingiphile Ngcobo.
With that said, it was the Lions of Teranga who hit the front as Niang's trickery on the left wing saw his strike deflected in beyond Khubeka in the 73rd minute.
At the death, Amajita were denied a shock equaliser as Leshabela's close range attempt was well saved by Senegal's number one.
The result means the West Africans face Mali in the final, who saw off Nigeria on penalty kicks. SA's youngsters will face the Super Eagles in a third and fourth place playoff.
However, the silver lining is that Amajita have guaranteed their place at the U20 World Cup by reaching the last four.