Downs put on an exquisite display of attacking football and brought AmaZulu’s unbeaten record away from home to an abrupt end.
With the win Sundowns remain unbeaten in the League – in some style.
Goals from Hlompho Kekana, Cuthbert Malajila, Dove Wome and a brace apiece from Katlego Mashego and second half substitute Katlego Mphela guided Downs to the top of the standings.
Sthembiso Ngcobo found the back of the net for Usuthu from the penalty spot.
Pitso Mosimane’s men continued their great form against the KwaZulu-Natal outfit and bounced back in some style from their Telkom Knockout loss to Platinum Stars at the weekend.
Kekana got the demolition underway, scoring in the second minute with a powerful effort from range, which took a deflection before clipping the underside of the post and ending up in the back of the net.
Malajila doubled the home side's lead in the 21st minute, reacting quickest to a Tebogo Langerman cross to score his third of the season.
And it was 3-0 to the Brazilians just a minute later, when Mashego turned his marker inside out before stabbing the ball past Tapuwa Kapini to open his account for the season and for his new club.
Downs looked unplayable and made it 4-0 on the stroke of half-time, when Wome played a neat one-two with Malajila before finding the back of the net via the post.
Craig Rosslee’s men went into the change-room with a mountain to climb after the break, and admittedly looked much better after the restart.
Usuthu pulled one back through Ngcobo in the 65th minute from the penalty spot, when the on-loan Kaizer Chiefs striker thumped the ball past Kennedy Mweene after Alje Schut was adjudged to have pushed Ayanda Dlamini inside the area.
'Mahoota' – last season's top scorer – put the game beyond any doubt 10 minutes from time, when he ran onto a pass from Mzikayise Mashaba before clinically placing the ball past a helpless Kapini in goal to make it 5-1.
Next, Mphela marked his return in style. He had only been on the park for two minutes when he fired a powerful volley into the back of the net to make it six.
And it was seventh heaven for the Brazilians two minutes into stoppage time, when Khama Billiat picked out ‘Killer’, who guided a fierce drive past the damaged AmaZulu skipper to end the night.