The Waratahs held on for a nail-biting 23-18 Super Rugby win over the Western Force at nib Stadium in Perth on Friday.
The Force came back from 17-3 down to take the lead deep into the second half.
But two late penalties from Berrick Barnes saw the visitors claim a hard-fought victory to retain their unbeaten record in Western Australia.
The result sees the 'Tahs provisionally take top spot in the Australia Conference while defeat left the Force with just 13 points from eight matches and needing a minor miracle to make the play-offs.
A first-half try from wing Tom Kingston after a neat dummy from Tom Carter on a counter-attack gave the visitors a 10-3 lead at the break.
The Waratahs moved further ahead soon after the restart thanks to a touchdown from flank Dave Dennis. Tatafu Polota-Nau's clever short lineout found Dennis, who casually strode in to expose an abysmal Force defence.
But the Force found their second wind and tries in quick succession from scrum-half Brett Sheehan and full-back Alfie Mafi cut the deficit to just two points on the hour mark.
And the fight back continued as fly-half David Harvey landed his second penalty of the evening to put the hosts ahead with a little over fifteen minutes left on the clock.
The Waratahs weren't to be denied however as Barnes took control of the game in the closing stages.
The Wallaby playmaker landed two late penalties to ensure his side stay firmly in the running for a play-off berth.
For Western Force:
Tries: Sheehan, Mafi
Pens: Harvey 2
Tries: Kingston, Dennis
Pens: McKibbin, Barnes 2
Yellow cards: Ma'afu (Force - 38th min); Foley (Waratahs -57th min)
Western Force: 15 Alfie Mafi , 14 Rory Sidey, 13 Nick Cummins, 12 Winston Stanley, 11 Cameron Shepherd , 10 David Harvey, 9 Brett Sheehan, 8 Matt Hodgson, 7 David Pocock (c), 6 Richard Brown, 5 Nathan Sharpe, 4 Toby Lynn, 3 Salesi Ma'afu, 2 Nathan Charles, 1 Pek Cowan.
Replacements: 16 Elvis Taione, 17 Kieran Longbottom, 18 Phoenix Battye, 19 Ben McCalman, 20 Josh Homes, 21 Ben Seymour, 22 Patrick Dellit.
Waratahs: 15 Bernard Foley, 14 Tom Kingston, 13 Rob Horne, 12 Tom Carter, 11 Adam Ashley-Cooper, 10 Berrick Barnes, 9 Brendan McKibbin, 8 Wycliff Palu, 7 Chris Alcock, 6 Dave Dennis, 5 Kane Douglas, 4 Dean Mumm, 3 Sekope Kepu, 2 Tatafu Polota-Nau, 1 Benn Robinson.
Replacements: 16 John Ulugia, 17 Paddy Ryan, 18 Sitaleki Timani, 19 Lopeti Timani, 20 Jono Jenkins, 21 Sarel Pretorius, 22 Daniel Halangahu.
Referee: Glen Jackson (New Zealand)