After one break by Mitchell and good support from Pretorius, the forwards rumbled at the Hurricanes' line in the first half, only to free it for the backs and for Pretorius to throw a wonky pass, spilled at the crucial moment.
So it became a grinding affair, more Waratah-oriented than Hurricane-friendly, with the Australians knocking over the penalties - giving plenty of time to reflect that the Canes had not beaten the New South Welshmen in their last four attempts.
But the Waratahs fumbled, livewire halfback TJ Perenara pounced and the Hurricanes swooped on the ball like student rioters on a loose Bill English comment. With hooker Dane Coles, prop Ben May and second five Tim Bateman prominent, the Hurricanes worked the ball well, ending with big winger Julian Savea blowing through the tackle of Waratahs' fullback Bernard Foley to score.
The Waratahs continued banging away, using their big men as assault troops - Wycliff Palu, Tatafu Polota-Nau and Sitaleki Timani - and gaining the edge up front. But still the crucial passes would not go where intended or would not stick; the Canes manned up, making their tackles and scrambling well.
So it continued - the Waratahs dominating field position and possession but making mistakes when they got to their opponents' 22. The second half scoring was restricted to penalties until the Canes made a rare excursion to Waratahs property - and promptly scored. Replacement Motu Matu'u dotted down after fine work from fullback Andre Taylor, No 8 Victor Vito and first five-eighths Beauden Barrett.
They wrapped it up with an easy try to Conrad Smith, cruelly demonstrating to the Waratahs how to score touchdowns and got the bonus point right on the hooter with a try to fresh halfback Chris Eaton - a soft score from a lineout. Vito had a big, busy game for the Hurricanes, as did Coles and Barrett was all class at first five. Flanker Brad Shields made an impact when he came on. Conversely, it wasn't a good night for Wallabies first five-elect Berrick Barnes, whose mistake in the second half led to Matu'u's try.
The Hurricanes needed this win to stay in touch with the top six and the play-offs. They have the Crusaders, a bye and the Chiefs to come. To have lost to the Wonky Waratahs would have been a signal that they were kidding themselves.
Waratahs 12 (B. Barnes 4 pens), Hurricanes 33 (J. Savea, M. Matu'u, C. Smith, C. Eaton tries; B. Barrett 2 cons, 3 pens). Halftime: 9-13.