A seven-pointer at the death saw the Waratahs edge the DHL Stormers 32-30 at DHL Newlands on Saturday.
It was just their third defeat of the season, but the bonus point they earned sees them keep their place at the top of Africa conference 1.
The DHL Stormers took the game to the Waratahs early on and won two penalties in opposition territory, but both attempts on goal from flyhalf Jean-Luc du Plessis were wide of the mark.
Instead it was the Waratahs who opened the scoring, as centre Kurtley Beale darted through to score the first try, which went unconverted for a 5-0 lead.
However, the DHL Stormers did not trail for long as a great flip pass from Nic Groom saw Schalk Burger score under the poles to put them 7-5 up.
The DHL Stormers’ second try was sparked by a break from Pieter-Steph du toit who surged into the Waratahs 22, and the big lock was on hand to finish it off as well as he crashed over from close range shortly afterwards.
The visitors had the final say before half-time, as an Israel Folau try saw them trail the DHL Stormers 14-12 at the break.
The hosts were first to score in the second half through a Du Plessis penalty, and the Waratahs responded soon afterwards with a penalty of their own from Foley.
The flyhalves exchanged penalties once again before the DHL Stormers were struck a major blow when wing Leolin Zas was shown a red card for colliding with another player in the air.
Despite that setback, the DHL Stormers were next to score through another Du Plessis penalty, but the Waratahs would have the lead soon afterwards as wing Rob Horne crossed for their third try to put them 25-23 ahead.
However, the DHL Stormers refused to lie down and after a powerful maul had driven them into the opposition 22, Du Toit took matters into his own hands and powered over for a try between the poles.
The Waratahs would have the final say when skipper Michael Hooper forced his way over for a try at the death which saw them claim a slender victory.
For DHL Stormers:
Tries: Burger, Du Toit 2
Cons: Du Plessis 3
Pens: Du Plessis 3
Tries: Beale, Folau, Horne, Hooper
Cons: Foley 4