Leading marksman Jeremy Brockie was also on target as ‘Matsatsantsa’ shocked their hosts who had Saber Khalifa scoring from the spot, advance to the final 4-2 on aggregate.
A 1-1 draw from the first leg three weeks ago gave the Tunisians a slight edge, but they were undone by a determined Supersport side that punished them for their sloppy defence.
Grobler gave ‘Matsatsantsa’ a lone goal lead at half time scoring on 16 minutes, heading home from a Thuso Phala cross, to silence the partisan crowd at the Olympic Stadium in Rades, near Tunis.
New Zealand-import Brockie doubled the lead on 53 minutes by finishing off a Teboho Mokoena assist for his 10th goal of the campaign.
Captain Saber Khalifa gave a glimmer of hope to Club Africain by reducing the deficit on 56 minutes from the spot after Morgan Gould had impeded him in the penalty area.
Four minutes past the hour mark, Grobler took the game beyond the hosts with the third goal with a low shot past Club Africai goalie Atef Dkhili.
This is the second time Supersport coach Eric Tinkler has guided a club to the final of the second-tier continental club championship. His first was in 2014 with Orlando Pirates, which lost to another Tunisian side, Etoile du Sahel.
No South African club has ever lifted the second most important title in continental club football, created in 2004 following the merger of the defunct CAF Cup Winners’ Cup and the CAF Cup.
At stake is a 1,250,000 US Dollars for the eventual winner.