Frustrated coach Stephen Larkham says his Brumbies "missed an opportunity" by losing to the Crusaders, leaving an arduous path to win their first Super Rugby title in 21 years.
Crusaders reserve hooker George Bell crashed over late on for a decisive try in a 33-31 win in Canberra on Friday, keeping the decorated New Zealand side second in the final standings, with Australia's Brumbies third.
The Chiefs sealed top spot with a 41-24 win over the Highlanders in Dunedin, aided by a hat-trick of tries to lock Tupou Vaa'i.
The top three finishers are finalised and all will stage home games in next week's first round of play-off fixtures under a new top-six format.
Home advantage has proved an important factor throughout the history of Super Rugby knockout matches.
If results go to seedings, the Brumbies will have to travel to New Zealand for their semi-final the following week.
It is a familiar scenario for a team who have qualified for the play-offs in eight of the last nine full editions of the championship, but never in the top two.
They haven't reached the grand final in that time.
Larkham noted their most recent top-two qualification was 2004, when they last won the title.
"It's been 21 years and every year we start the season and talk about top two as a goal," Larkham told journalists on Friday.
"So yeah, we've missed an opportunity there again. It makes it a little bit harder for us. We're going to need a little bit of luck to get a home semi-final but that's out of our control now."
Larkham said regular captain Allan Alaalatoa should return from injury at prop for the Brumbies next week, when they host the fourth-placed finishers. That will be either the Hurricanes or Reds.
He was unsure about the fitness of fellow Wallaby Len Ikitau after the key midfielder limped out of the Crusaders match with a leg problem.