The Highlanders were ahead with seconds left but could not close out the game in a match where it almost overcame the loss of two All Blacks and conceding 30 unanswered points.
The Highlanders looked to be out of the game at 30-19 down with the Brumbies clicking into gear, but a gutsy last quarter of an hour from the home side almost got the Highlanders into the winning column.
Losing captain Jimmy Cowan after just 16 minutes and then vice-captain Jamie Mackintosh in the first half, was a huge hurdle to overcome and the side all but made it.
In the final 15 minutes the Highlanders hit rucks with more steel, managed to hold on to the ball and get more territory while the loose forwards managed to get in behind their opposites.
Replacement prop Chris King burrowed over to get the side close and then his fellow replacement, hooker Jason Rutledge jumped over a ruck and scored with two minutes to go.
Daniel Bowden's conversion hit the post, giving the home side a one-point lead, with less than 100 seconds left.
But the Highlanders could not control the kick-off and the Brumbies set up for a drop goal, with first five-eighth Christian Lealiifano knocking over the winning points from about 30m out.
It was a thrilling match to start the season, with the Highlanders bursting out of the blocks, scoring three quick tries inside 20 minutes, to lead 19-0.
But they were like sheep caught in the headlights for the next 40 minutes, as the Brumbies dominated both possession and territory.
The Brumbies came back to 19-7 at half-time and appeared to be cruising as they went ahead, scoring 30 points in 25 minutes, dominating the line-out and controlling rucks and mauls.
Wallabies captain Stirling Mortlock was his usual cannonball self and helped himself to two tries.
When Mark Gerrard strolled over after a bad defensive lapse by the Highlanders backline, the match looked all but over, with 25 minutes left.
But slowly the Highlanders got the ball, referee James Leckie started finding some penalties for the home side, and the momentum swung back.
Bowden had a fine match at first five-eighth but will rue his missed conversions, while replacement halfback Sean Romans looked good when he came on.
Adam Thomson made plenty of tackles, while fellow loose forward Alando Soakai got through plenty of work. Prop Clint Newland ran himself to a standstill, as did hooker David Hall.
The Highlanders made a great start to the match, with centre Jason Shoemark scoring after just six minutes, the try stemming from a good run by Johnny Leota.
Less than five minutes later, Otago was on the board again.
Jimmy Cowan took a quick tap, threw a fine ball to Israel Dagg who put Fetu'u Vainikolo into space and the Tongan flier did the rest.
Bowden then put together a fine individual effort. Receiving the ball just 25m out from his own line, he produced a fine chip and gather and could not be caught by the covering defence.
The best for the Brumbies was Mortlock, while Gerrard looked composed.
George Smith looks to have lost none of his ball-stealing ability in his 10th season of professional rugby, while prop Nic Henderson got around the paddock.
• Brumbies 33 (Stirling Mortlock 2, Adam Ashley-Cooper, Mark Gerrard tries, Gerrard 2 penalty goals, 2 conversions, Christian Lealiifano drop goal) (Jason Shoemark, Fetu'u Vainikolo, Daniel Bowden, Chris King, Jason Rutledge tries, Bowden 3 conversions) Half-time: 19-7 Highlanders. Crowd: About 4000.
