The Brumbies recorded a 23-6 victory over the 'Tahs on Saturday in a win that moves them nine points clear at the top of the Australian conference.
It was far from a classic in Canberra as the in-form hosts put in a professional performance to cruise into a well-earned bye week on 35 points.
Their tries came at the perfect time in the game and ultimately proved the difference as Henry Speight's score on half-time and Andrew Smith's five minutes after the interval did the damage.
Micheal Foley's side, who face the Bulls at home next Friday, could only trouble the scorers via the boot of number nine Brendan McKibbin due to a fine Brumbies defence that was rarely breached.
The Brumbies entered the game on the back of good performances in South Africa, most recently claiming a bonus-point win against the Lions. Meanwhile the Waratahs fell to the Crusaders last week and have been struggling for line-breaking threats due to the continued absence of Drew Mitchell, Lachie Turner and also Rob Horne.
They may now have to add Wallaby hooker Tatafu Polota-Nau to their unavailable players after the powerful front-row left the field before the break after taking some heavy knocks.
Action in Canberra was, as mentioned, not high in the entertainment stakes and as the half-time siren sounded there were only two penalties apiece on the board by fly-half Christian Lealiifano and 'Tahs man McKibbin. But on that siren came a moment of brilliance from winger Speight, who ghosted through two tacklers on the right to make it 13-6 at the interval.
Following a half-time talking to from Jake White, the Brumbies continued in the second period from where they left off in the first as patient phase play led to outside centre Smith crashing over. Lealiifano's extras moved the Brumbies up to a 20-6 lead on 45 minutes.
Only Lealiifano's penalty on 72 minutes troubled the scorers until the final whistle though, as the Brumbies' defence shut up shop to keep the Waratahs' limited running threats quiet.
Tries: Speight, Smith
Con: Lealiifano 2
Pen: Lealiifano 3
Pen: McKibbin 2
Brumbies: 15 Jesse Mogg, 14 Henry Speight, 13 Andrew Smith, 12 Pat McCabe, 11 Joe Tomane, 10 Christian Lealiifano, 9 Nic White, 8 Fotu Auelua, 7 Michael Hooper, 6 Ben Mowen (c), 5 Sam Carter, 4 Scott Fardy, 3 Dan Palmer, 2 Stephen Moore, 1 Ben Alexander.
Replacements: 16 Anthony Hegarty, 17 Ruaidhri Murphy, 18 Peter Kimlin, 19 Ita Vaea, 20 Ian Prior, 21 Robbie Coleman, 22 Tevita Kuridrani.
Waratahs: 15 Adam Ashley-Cooper, 14 Atieli Pakalani, 13 Tom Kingston, 12 Tom Carter, 11 Peter Betham, 10 Berrick Barnes, 9 Brendan McKibbin, 8 Wycliff Palu, 7 Jono Jenkins, 6 Dave Dennis, 5 Kane Douglas, 4 Sitaleki Timani, 3 Sekope Kepu, 2 Tatafu Polota-Nau, 1 Benn Robinson (c).
Replacements: 16 John Ulugia, 17 Jeremy Tilse, 18 Dean Mumm, 19 Lopeti Timani, 20 Rocky Elsom, 21 Sarel Pretorius, 22 Daniel Halangahu.
Referee: Chris Pollock (New Zealand)
Assistant referees: James Leckie (Australia), Richard Goswell (Australia)
Television match official: Matt Goddard (Australia)