Masandawana looked to leave no stone unturned having won the first-leg by a narrow margin last Sunday at home, while AS FAR had their work cut out to get any advantage into the overall contes.
It was a difficult start for the Tshwane giants against the hostile home crowd and the lead was under threat when a cross into the box found captain Mohamed Hrimat, who fired went over the top.
Sundowns refused to be overawed and enjoyed their first chance midway in the first half after a powerfully struck long-range shot by Tashreeq Matthews flew narrowly wide of the upright.
Drama unfolded ten minutes towards the break when the Video Assistant Referee (VAR) took centre stage and a penalty was given to the host after Divine Lunga was deemed to have brought down Red Slim, which allowed Hrimat to step up and dispatch the spot-kick.
Masandawana, however, were level in the final minute of stoppage time after Matthews flicked a cross from Brayan Leon onto Teboho Mokoena, who volleyed in off the underside of the crossbar to make it 2-1 on aggregate to the South African side.
Second Half:
Ahead of the second half, Sundowns freshened up their stall as Marcelo Allende came on in the place of Kutlwano Letlhaku while the home team were unchanged from the first stanza.
Sundowns remained compact buoyed by the away-goal and looked to stretch their overall cushion with Leon closing in following a long ball up-field, but Tagnaouti managed to make a vital save.
However, the South Africans were given a scare a little into the second half as Hrimat threatened to complete his brace when he rose on the end of a corner-kick and nodded narrowly wide of the net.
VAR came in the spotlight again in the final 20 minutes when the referee awarded the host another penalty after Williams fouled Slim, but the Bafana Bafana skipper redeemed himself and smothered the subsequent spot-kick taken by Hrimat.
Sundowns very nearly got in front minutes later when a forward run by substitute Arthur Sales led to a through pass for Jayden Adams to pick out the far corner, but the midfielder sent his effort wide of the upright.
As the match started to wind down, no victor emerged on the night but the Brazilians had done just about enough to land the Champions League title for the second time while coach Miguel Cardoso gets his first title at the third attempt.
