The winning goal came in the 60th minute when Gaston Sirino latched onto a long pass, beat the offside trap and buried the ball in net.
The star-studded Brazilians piled on the pressure from the start, but could not find a way past Celtic goalkeeper Patrick Tignyemb.
Pito Mosimane’s side created one chance after the other, but poor finishing let them down. Celtic also defended outstandingly, with right-back Lourenzo Gordinho doing well in the eighth minute to deny Tebogo Langerman with the keeper beaten.
The dangerous Andile Jali had a good chance in the 14th minute to put Sundowns ahead, but he shot wild and wayward with only the keeper to beat.
That seemed to be the order of the day for Sundowns, who created 12 scoring chances in the first half alone. The Celtic defence was kept extremely busy and were let off the hook in the 21st minute when defender Mosa Lebusa could not keep his header on target.
Celtic were lucky when referee Daniel Bennett wrongfully blew for offside after Toni Silva was put through. Sirino found himself in an offside position, but he had not played the ball.
Celtic started the second stanza on a positive note, but it was Sundowns who had the first scoring opportunity. Themba Zwane received a pass in the box, but his shot at goal was hopelessly off target.
Sundowns had another opportunity in the 55th minute after Sirino out-sprinted Gordinho. The Sundowns’ striker, however, did not have the power to get the ball past Tignyemb.
Sirino eventually made the breakthrough with an hour played, and for once Tignyemb had no answer for the Sundowns’ striker.
Steve Komphela’s Celtic pressed hard for the equaliser late in the match, but did not have any success with Sundowns’ keeper Denis Onyango not putting a foot wrong.
Celtic’s best chance came in the 93rd minute when the visitors had a freekick inside the box. Victor Letsoalo sent the ball past the Sundowns’ wall, but it was not on target.
It was a good victory for Sundowns, but they will have to work on their finishing if they are to challenge for the prestigious cup title.
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