The Western Force won their first Super Rugby game on Australian soil in 2011 after defeating the Brumbies 27-19 in Canberra on Sunday.
With the game hanging on a knife's edge, Force winger David Smith crossed over two minutes from full-time for his second try and the match-winner.
James O'Connor added salt to the Brumbies' wounds by kicking over the conversion that denied the hosts a losing bonus point.
In a rather dull affair, the Aussie derby between two of the tournament strugglers only really came to life late in the second half with the lead changing hands several times before Smith sealed the deal at the death.
Matt Giteau contributed all of his side's points with a converted try and four penalties, but in the end it wasn't enough as O'Connor made up for two missed shots at goal with a try of his own and ten points with the boot.
The Brumbies looked to be cruising at 10-0 ahead thanks to a Giteau's try under the sticks set up by centre Christian Lealiifano, but the Force hit back with a length-of-the-field score by O'Connor.
With the Brumbies hot on attack, the ball was spilled and Force centre Rory Sidey hacked ahead. O'Connor gave chase, showed off some impressive soccer skills before picking up and diving over for the try. Willie Ripia converted to take the scores to 10-7 at half-time.
Giteau extended his team's lead shortly after the interval with another penalty, but the Force struck back straight away from the restart with Smith's first five-pointer after O'Connor drew two defenders to put the New Zealander over in the corner. O'Connor touchline conversion gave the Force the lead for the first time in the match.
The lead would change hands three more times as Giteau and O'Connor battled it out with the boot, until Smith's try - set up by Ripia from an attacking scrum - ended Sunday's proceedings.
Pens: Giteau 4
For Western Force:
Tries: Smith 2, O'Connor
Cons: O'Connor 2, Ripia
Pens: O'Connor 2
Brumbies: 15 Matt Toomua, 14 Pat McCabe, 13 Andrew Smith, 12 Christian Lealiifano, 11 Francis Fainifo, 10 Matt Giteau (c), 9 Josh Valentine, 8 Ita Vaea, 7 Michael Hooper, 6 Peter Kimlin, 5 Mark Chisholm, 4 Ben Hand, 3 Dan Palmer, 2 Anthony Hegarty, 1 Ben Alexander.
Replacements:16 Elvis Levi, 17 Salesi Ma'afu, 18 Colby Faingaa, 19 Julian Salvi, 20 Patrick Phibbs, 21 Tyrone Smith, 22 Adam Ashley-Cooper.
Western Force: 15 Pat Dellit, 14 Nick Cummins, 13 Rory Sidey, 12 James O'Connor, 11 David Smith, 10 Willie Ripia, 9 Brett Sheehan, 8 Ben McCalman, 7 Jono Jenkins, 6 Richard Brown, 5 Nathan Sharpe (c), 4 Sam Wykes, 3 Tim Fairbrother, 2 Ben Whittaker, 1 Kieran Longbottom
Replacements: 16 Nathan Charles, 17 Pek Cowan, 18 Tom Hockings, 19 Tevita Metuisela, 20 James Stannard, 21 Gene Fairbanks, 22 Alfie Mafi.
Referee: Keith Brown (New Zealand)