The Brumbies moved to the top of the Australian conference table after securing a hard-fought 25-15 win over the Stormers in Canberra.
The visitors, who are yet to win on their Australasian tour, will be kicking themselves as poor goal-kicking from their fly-half Peter Grant - he squandered eight points via two penalties and a conversion - proved costly.
After missing an early three-pointer, Grant succeeded with a penalty in the seventh minute but the home side struck back with a well-executed try from Robbie Coleman three minutes later.
The Stormers' defence was caught flat-footed thanks to several decoy runners before Matt Toomua ghosted through a gap in the visitors' back-line. Toomua still had work to do and drew in a defender before getting his pass away to Coleman, who was rewarded with the try in the right-hand corner after coming off the opposite wing.
Nic White landed a difficult place-kick from up against the touchline which gave the hosts a 7-3 lead after 10 minutes.
For the next 10 minutes there were several attacking forays from the Stormers and they were eventually rewarded in the 20th minute when, after initially setting up a ruck close to the Brumbies try-line after a line-out, Duane Vermeulen got the five-pointer after bursting through two tackles.
Grant added the extras but two penalties from White - in the 33rd and 39th minutes - gave the Brumbies a 13-10 lead at the break.
Earlier, the Stormers were reduced to 14 men when Tiaan Liebenberg was sent to the sin bin in the 30th minute for a tip tackle on Ben Mowen.
Like the opening period, the second half was a cautious affair with both sides kicking for territory and the Brumbies clung to their three-point lead for the most of the half.
The game opened up in bizarre fashion in the 63rd minute when Coleman was the beneficiary of a poor error in judgement from Kobus van Wyk. While fielding a ball close to his try-line, the young Stormers wing opted to shepherd the ball into touch but to his surprise, Coleman gathered the bouncing ball and dotted down.
White failed to with the conversion but with the Brumbies leading 18-10, and time running out on the clock the Stormers became more daring on attack.
Their efforts were rewarded in the 75th minute when Juan de Jongh crashed over after slipping past two defenders. Grant had an opportunity to cut the deficit to a single point but missed with his conversion attempt.
This followed shortly after he struck an upright when the Stormers were awarded a penalty and instead of holding a 20-18 lead, the visitors were still trailing by three points.
They didn't get close to adding to their tally, however, and were cruelly denied a bonus point when referee Glen Jackson awarded a penalty try to the hosts after the Stormers' scrum buckled under pressure on their five-metre line.
Tries: Coleman 2, penalty try
Cons: White 2
Pens: White 2
Try: Vermeulen, De Jongh
Yellow card: Liebenberg (30th minute, tip tackle)
Brumbies: 15 Jesse Mogg, 14 Joe Tomane, 13 Andrew Smith, 12 Pat McCabe, 11 Robbie Coleman, 10 Matt Toomua, 9 Nic White, 8 Ben Mowen (c), 7 Jarrad Butler, 6 Jordan Smiler, 5 Sam Carter, 4 Scott Fardy, 3 Ben Alexander, 2 Stephen Moore, 1 JP Smith.
Replacements: 16 Siliva Siliva, 17 Ruan Smith, 18 Ruaidhri Murphy, 19 Jack Whetton, 20 Lachlan McCaffrey, 21 Michael Dowsett, 22 Stephan Van Der Walt, 23 Lionel Cronje.
Stormers: 15 Gio Aplon, 14 Kobus van Wyk, 13 Jean de Villiers, 12 Damian de Allende, 11 Sailosi Tagicakibau, 10 Peter Grant, 9 Nic Groom, 8 Duane Vermeulen, 7 Siya Kolisi, 6 Deon Fourie, 5 Michael Rhodes, 4 Ruan Botha, 3 Frans Malherbe, 2 Tiaan Liebenberg, 1 Steven Kitshoff.
Replacements: 16 Stephan Coetzee, 17 Oliver Kebble, 18 Brok Harris, 19 Jurie van Vuuren, 20 Nizaam Carr, 21 Louis Schreuder, 22 Demetri Catrakilis, 23 Juan de Jongh.
Referee: Glen Jackson (New Zealand)