And falling one game short of another grand final berth will be even more painful as they watch their NSW Waratahs rivals aim to break through for their maiden title.

The Brumbies lost to the Waratahs 26-8 in an Australian rugby blockbuster in front of 38,800 fans at Allianz Stadium on Saturday night.

The Waratahs will host the Canterbury Crusaders in the grand final next weekend and are perfectly positioned to win the club's first Super Rugby title.

But the Brumbies will limp back to Canberra on Sunday morning, wondering what could have been after they failed to fire with their season on the line and farewelling 17 players and staff.

The Waratahs scored three tries to one in an absorbing match punctuated by referee Jaco Peyper struggling to keep pace with the game.

The Waratahs' attack has been lauded all year, but it was the star-studded NSW side's defence which lifted them into the grand final.

The decisive moment came just minutes after half-time when Christian Lealiifano had a chance to level the score at 11-11.

Lealiifano's woes with the boot have been well-documented this year, struggling to find his rhythm after having ankle surgery eight months ago.

He missed a penalty goal from almost directly in front and Brumbies' heads dropped.

Instead of scores being locked up just after the break, the Waratahs raced to the other end, Kurtley Beale stole the ball off Jesse Mogg and scored to break the game open.

It was one of only two chances for the Waratahs in the second half and they scored off both opportunities.

It was a frustrating end to what the Brumbies hoped would be a championship-winning campaign to erase the pain of last year's grand final defeat to the Waikato Chiefs.

"It was a tough night out, the Waratahs defended superbly,'' outgoing Brumbies director of rugby Laurie Fisher said.

''I thought we played stoically all night, we hung in and hung in but, in the end, the better team won.

"I think we can be proud of what we achieved. We had plenty of opportunities but we weren't able to compete with the pressure they had, legal or illegal [pressure]."

The Brumbies will say goodbye to some of their inspirational leaders.

Skipper Ben Mowen is off to France. Fisher will join Gloucester. The management team will split up and a host of players will leave the capital.

Club great Stephen Larkham will take over as the sole coach and recruit at least one more assistant to help the Brumbies end their wait for another championship.

Referee Peyper refused to punish the Waratahs in the second half, despite the home side giving away eight penalties when the Brumbies were on the attack.

But in the end the Brumbies only had themselves to blame as they fell short of back-to-back grand final berths.

"The Waratahs were too good, we put pressure on them but they held it," said Brumbies prop Ben Alexander.

"They deserve credit, and hopefully they can get it done next week.

"Our season was disappointing. We were too patchy, we played some good footy and there's plenty to be proud of, but we're disappointed with that finish."

Brumbies winger Henry Speight scored the team's only try, but his night was soured by a hamstring injury which could further delay his Test debut for the Wallabies.

All three Waratahs tries came against the run of play - Alofa Alofa capitalising on an intercept, Kurtley Beale stealing the ball off Jesse Mogg to score and Bernard Foley finishing off a long-range play to put the final nail in the Brumbies' season.

"We had our chances to score, but we missed them. It was frustrating to watch," Larkham said.

"It's disappointing to go out of the competition at this stage, it's a good season to get to the finals but as an organisation we pride ourselves on winning Super Rugby championships.

"We've fallen short and therefore it's disappointing. I thought everything was lining up for us, we just needed a bit of luck against the Waratahs and it just didn't happen."

Mowen said his side pushed too many passes and the Waratahs handled pressure moments better.

"I'm really disappointed, I really feel like this side deserves some sort of finality ... a championship," Mowen said.

"That's there for next year, I just felt the work we'd done and the development we'd had, I could see it ending [in a championship] and I'm disappointed it didn't.

"I think you can say the ACT-NSW rivalry is well and truly alive."

NSW WARATAHS 26 (Alofa Alofa, Kurtley Beale, Bernard Foley tries; Bernard Foley 3 penalties, conversion) bt ACT BRUMBIES 8 (Henry Speight try; Christian Lealiifano penalty) at Allianz Stadium on Saturday night. Referee: Jaco Peyper. Crowd: 38,800.