The Australian side remain in the hunt to win their conference but the Kiwis are in serious danger of missing out on a wild card spot.
Bernard Foley scored a try and booted 15 points for the Waratahs with Israel Folau and Dave Dennis also crossing while Bundee Aki scored both tries for the Chiefs.
Aaron Cruden booted the Chiefs into an early lead but Foley responded with a penalty of his before Alofa Alofa had a try chalked off by the TMO.
The visitors did not have long to wait for their opening score, though, as Folau went over after good work from Adam Ashley-Cooper and Foley added the extras.
Another Foley penalty made the lead 10 points at half-time but the Chiefs cut the gap 10 minutes after the interval with Aki pouncing on a Cruden chip through and the fly-half converted.
A Kurtley Beale penalty added three more to the Waratahs tally but the home side soon had the lead when Aki touched down Tom Marshall's grubber and Cruden again successfully converted.
From there on in, however, it was all Waratahs with Foley booting a penalty before Dennis crashed over and Foley added the extras.
Foley then added another seven points as he converted his own score in the final minute to seal the win.
- Sports & Recreation
- Bernard Foley
- Israel Folau
- Aaron Cruden
- Dave Dennis
- Bundee Aki
- Alofa Alofa