The Tshwane side scored three minutes into the game and three minutes from time, both strikes coming from Katlego Mphela, and did create several more good chances to score, but at times they were also forced onto the back foot as Aces enjoyed several sustained periods of ball possession.
There were certainly positives to be taken from the game for Sammy Troughton and his men, but Aces will need to work on their final touch around the opposition box, and also defending in their own area, if they are to enjoy success.
Downs were off to a dream start when Mphela’s 30-yard free kick skimmed along the ground and sneaked in off the near post with less than three minutes on the clock: welcome to the PSL Black Aces!
However, following the early setback, Aces slowly worked their way back into the game, enjoying a good spell of possession before creating a great chance to level matters in the 16th minute.
Gilbert Mushangazhike was the supplier, picking out Madoda Motha with an accurate cross, but Motha stroked the ball wide of goal from only eight yards out.
Two minutes later Sundowns keeper Brian Baloyi flapped at a cross and failed to get telling contact to the ball which fell to Gilbert Rudiger, but the former FC AK defender skewed his shot with the goal at his mercy.
Aces goal keeper Nascent Nkhwashu had to be alert in the 30th minute when Mabuthi Khenyeza bore down on goal after beating the off-side trap, doing well to rush off his line and steal the ball off the Downs striker.
Nkhwashu was fortunate from the resultant corner when he dropped the ball before managing to scoop it up right on the line.
But by this stage of the game Aces were more than matching their more illustrious opponents and created another good chance through Rudiger, who cut inside and fired goal-wards, but the goal-bound shot struck the head of Derrick Spencer.
Sundowns worked hard in the early stages of the second half to wrestle back the initiative, but Aces did well to hold onto the ball.
Zimbabwean striker Mushangazhike seemed to be Aces best bet for a goal and in the 56th minute he struck a venomous 30-yard shot which resulted in Baloyi making a good instinctive save.
But eight minutes later Sundowns should have doubled their lead from a rare attack when an accurate free kick from Gareth Ncaca picked out Papi Zothwane at the back post, but the former Arrows midfield maestro volleyed wide with the goal at his mercy.
Next it was the turn of Vuyo Mere to waste a chance when he burst through the centre of the Aces defence before putting an attempted chip on the turn wide of the mark.
Zothwane made it a hat-trick of missed chances in the 82nd minute when a clumsy first touch brought an end to a good move involving Kurt Lentjies and Esrom Nyandoro.
Downs were finally able to make a chance count three minutes from time when some poor defending allowed Mphela to pounce from close range to net his brace.