The Brumbies staged one of the biggest upsets of the Super Rugby season with a 22-14 victory at Suncorp Stadium.
Fly-half Matt Giteau was the star, kicking six goals from six attempts. He also won his personal battle with the Reds' incumbent Wallabies fly-half Quade Cooper, kicking 17 points while Cooper missed two of five attempts and finished with nine points.
Compounding the loss for the Reds was a serious injury to Test winger Digby Ioane, who was knocked out cold in the second half by number eight Ita Vaea.
A second-half fightback lifted the Hurricanes to a resounding 38-27 win over the Lions in Wellington. Trailing 20-8 after tries by Jaco Taute and Doppies La Grange cancelled out an early five-pointer by Aaron Cruden, the Hurricanes looked to be in trouble as defensive lapses and an inability to control the ball hampered them.
But a Hosea Gear try just before half-time sparked the home side and they kept up the pressure in the second spell with Ma'a Nonu adding a third try and Gear completing his double to give the Hurricanes back-to-back wins for the first time this season.
Cruden continued his fine goal-kicking form with four penalties and three conversions for an 18-point haul.
The Sharks saw off the Cheetahs 23-18 in Bloemfontein to pick up the win they needed to maintain their Super Rugby play-off hopes. The home side, with little to play for, led 11-6 at half-time at Free State Stadium - with Sarel Pretorius' try making the difference as both teams kicked two penalties.
However, Lwazi Mvovo and JP Pietersen crossed the whitewash in the second half to give the Durban-based team a victory which improves their chances of post-season action, despite another try from Riaan Viljoen just before the end.
The Blues suffered their third Super 15 loss in succession as they went down to a 16-11 defeat against the Chiefs at Eden Park.
Both sides managed a try apiece - Tana Umaga for the visitors and Jared Payne for the Blues - but in the end it was the kicking that proved decisive, with Stephen Donald sending over a conversion and three penalties against Luke McAlister's two.