The South Africans qualified after beating Nigeria in their semifinal on Wednesday, and Mali booked their place this afternoon with a 2-1 victory against Guinea.
Mali took the lead on 24 minutes through Sekou Koita, but Aboubacar Traore leveled matters just after the break.
But Aly Malle got what proved to be the winner on 52 minutes courtesy of a beautiful curling free-kick.
Amajimbos and their Malian counters will meet in the Final at the Stade Seni Kountche in Niamey on Sunday.