The Brumbies ended a 15-year winless streak against the Crusaders on Saturday, posting a dramatic 31-24 win that leaves the defending champions with little hope of reaching the Super Rugby Pacific playoffs.
A penalty try after the fulltime hooter consigned the Crusaders to a record 10th defeat of the season, leaving them with only a small mathematical chance of playing in next month's quarterfinals.
Trailing 17-7 at halftime, the 13-time champions from Christchurch played some of their best rugby of a disjointed campaign to level the scores entering the final five minutes.
However, an 80th-minute penalty shot at goal from Brumbies fly-half Noah Lolesio struck an upright before Crusaders lock Quinten Strange illegally batted the ball over the dead ball line.
Referee Ben O'Keeffe deemed a Brumbies' try would probably have been scored without Strange's foul play, awarding a penalty try which was disputed by some of the Crusaders players.
Captain Codie Taylor couldn't hide his frustration.
"We gave ourselves a crack but it's a tough way to finish a game like that," Taylor said.
"I'm proud of the boys. There's a lot of effort out there but we can't quite string it together."
Brumbies captain Allan Alaalatoa expressed relief after a 10th win left them in third place with two rounds remaining in the regular season.
He said they were determined to beat the Crusaders for the first time since 2009.
"That was something that was spoken about a few times during the week," he said.
"It's special, because we still know they're a quality side."
The Crusaders boasted a dominant scrum but a malfunctioning lineout and a propensity to throw loose passes once again let them down.
Brumbies fullback Tom Wright was a constant threat and scored two of their four tries while Crusaders winger Sevu Reece crossed for his 12th try of the season, three more than any other player in the competition.
Earlier, Suva-born Suliasi Vunivalu was sent off in a homecoming to forget as the Reds lost 28-19 to the Fijian Drua.
Reds winger Vunivalu was shown two yellow cards - both for foot-tripping - resulting in a red card that left the visitors one man down for much of the second half in heat-sapping Suva conditions.
The eighth-placed Drua notched a fifth win from six home matches this season, with captain Tevita Ikanivere crossing for two tries.
They were also awarded an early penalty try, conceded by Vunivalu when he tripped Kitione Salawa as the Drua flanker closed on the try-line.
The home side stayed in front throughout, aided by Vunivalu's trip on opposite number Selestino Ravutaumada during a Drua attacking raid soon after the interval.
The Reds remain fifth in the table, but defeat has ended their hopes of a home quarterfinal.