For the Brumbies, the defeat consigned the Australian conference leaders to the role of hopeful spectators after they failed to earn the point which would have booked their ticket to the playoffs.
They will now have to rely on the Waratahs to prevent the Reds from securing a bonus-point victory later tonight, otherwise they will be left sweating on a host of other results.
The Blues began the game with a spell of concerted pressure deep in Canberra territory and it wasn't long before they converted that pressure into points.
Piri Weepu had already put one penalty off the post when he elected for a quick tap near the line and the strategy paid off when, after a series of attacks around the ruck, Liaki Moli burrowed his way over from close range.
From the kickoff, the Blues picked up right where they left off. The Brumbies had barely set foot in the Blues' half when Daniel Braid made it 14-0, finding himself in space on the left after the ball passed through several sets of hands.
After a penalty, the Brumbies edged closer thanks to a scintillating solo run from Henry Speight. There appeared to be little on when Speight received the ball on the right sideline, but the Fijian winger showed speed to run outside two Blues and flair to step inside two more and reduce the deficit to four.
Just when it appeared the Blues' fast start was nothing more than an anomaly, the visitors turned on the style to score their third try. A break down the left from Charles Piutau was backed by several last-ditch passes to keep the move alive, before Hadleigh Parkes eventually waltzed through three defenders to make it 21-13.
The halftime break allowed both teams to catch their breath after a frantic first half and the second spell started at a much more sedate pace, with two penalties from Weepu pushing the Blues' lead to 11.
Worsening conditions prevented the type of attacking rugby on show before the break, and the Blues appeared content to protect their lead and attempt to spoil the Brumbies' season.
The hosts failed to force their way through the Blues, squandering a large share of possession and showing little imagination if the face of a resolute rearguard to leave their playoff fate in the hands of others.
Brumbies 16 (Speight try; Holmes 3 pens, con)
Blues 30 (Moli, Braid, Parkes tries; Weepu 2 pens, 3 cons, Hobbs pen)
HT: 13-21