It was a welcome return to form by Shalulile, who has struggled to find the net lately after finishing joint leading Premiership scorer last season.
Victory stretched Sundowns’ unbeaten league run across two seasons to a record-extending 47 matches since losing to Pretoria neighbours SuperSport United in September 2022.
They will be crowned champions of the richest national league in Africa on Thursday if they defeat eighth-placed Kaizer Chiefs in Johannesburg.
Fifth-placed Galaxy had a chance to grab an added-time consolation goal but Bernard Parker, returning to action after breaking his leg last October, had a penalty saved by Ronwen Williams.
A miserable night for the visiting team included the sending off of substitute Orebotse Mongae on 85 minutes for a tackle from behind on Bongani Zungu, who retired injured.
With Zungu unable to continue after Sundowns had made five substitutions, the final minutes became a 10-a-side match at Loftus Versfeld, a stadium Sundowns share with the Bulls rugby team.
Sundowns demonstrated their strength in depth as they made six changes to the side beaten by Esperance of Tunisia in a CAF Champions League semi-final last Friday and still dominated Galaxy.
© Agence France-Presse
Photo: Twitter @unplayableZA