The Brumbies stumbled at their biggest challenge of the season, suffering a 48-23 defeat at home to bring the Canberra side crashing back to earth winning four of its first five games.

But the Chiefs came to town with a reputation as entertainers and they lived up to the hype as they inflicted the Brumbies' biggest defeat at Canberra Stadium in the club's history.

The Chiefs' 48 points were the most conceded by a Brumbies team in the capital since the start of the competition in 1996 and the most conceded in any game since 2011.

It was a major shock for a team that prides itself on a rock-solid defence and the Chiefs showed they're on a different level to any other title contender so far this year.

The heavy defeat is set to be compounded with the SANZAAR duty judicial officer citing star flanker David Pocock for allegedly acting in an unsportsmanlike manner when defending a Chiefs' rolling maul in the 74th minute.

The red-hot Chiefs went on a second-half rampage to turn on some razzle-dazzle play, and the end margin didn't reflect that the Brumbies were in the contest for most of the game.

"It was really disappointing ... we knew before the game that the last 20 or 30 minutes were going to be really important," Moore said.

"That's where they ran away with the game. It's not good enough.

"We've got a bye now so we've got to take stock, we've had a big six weeks but there's a long way to go so we've got to dust ourselves off and go again."

The 25-point win extends the Chiefs' lead at the top of the ladder and blows open the Australian conference as the Brumbies, NSW Waratahs and Melbourne Rebels jostle for positions.

Brumbies coach Stephen Larkham lamented poor decisions in certain areas of the field that gave the high-flying Chiefs a chance to pounce, and the visitors attacked with absolute precision.

Playmaker Aaron Cruden's brilliant left foot cross-field kick late in the second half that landed in winger James Lowe's arms for a try typified the Chief's brilliance.

Chiefs fullback Damian McKenzie - who leads the competition in tries, points and run metres - was outstanding again as the Hamilton-based side ended an eight-year drought in Canberra.

They scored six tries to two and tore the Brumbies apart in open field.

"We were still in the game with 20 minutes to go at 29-23, but there were a couple of areas and there are some skills in certain areas of the field that we need to work on," Larkham said.

"But that's why the Chiefs are on top of the table. They're a side that can make a line break from anywhere and capitalise on that - they did that in the last 20 minutes."

The crowd of 12,896 were treated to a ding-dong battle of top-shelf rugby as the best New Zealand team and best Australian team threw everything at each other despite being on weary legs following respective around-the-world tours.

The Chiefs have gone from New Zealand to South Africa on to Argentina back to New Zealand and then to Canberra in the past four weeks.

In the same period the Brumbies have gone from Canberra to Perth to Cape Town and Bloemfontein before returning home.

It took its toll on powerful No. 8 Ita Vaea, who lasted just 18 minutes before he had to leave the field with cramps.

Brumbies lock Sam Carter suffered a head knock but isn't expected to miss any games.

The Brumbies lacked a clinical edge to capitalise on their opportunities and then the Chiefs turned on the afterburners to blast clear.

The Chiefs are on a different planet this year with their attack and flamboyance, and they showed why no team in the competition can match them when it comes to broken play.

They found gaps in a usually-sound Brumbies defence and threw flick passes, no-look offloads and brilliant support to have the home side scrambling to protect their line.

"We're pretty lethal from turnover pill and counter attack. It was a bit of a scratch start so we put pressure on ourselves when we didn't exit our end," said Chiefs coach Dave Rennie.

"We've got a massive amount of respect for the Brumbies, I've coached a couple of teams that have come over here. One we got an absolute bath and one was a two-point nail-biter.

"It's tough to win in Canberra, they've got an impressive back and and a pack that can give you gain line. We're really rapt."

Scott Sio and Scott Fardy scored tries for the Brumbies to stay in the battle, but Chiefs pivot Cruden had the magic touch when he put a deft kick over the top that landed in the arms of winger Lowe for his second try.

Moments later the Chiefs went almost the length of the field with another outstanding effort that involved a chip over the top, flick passes inside and flying support play for Brad Weber to score.

Weber's try killed off any hope of a Brumbies comeback and McKenzie had the last laugh with his seventh try of the season to end the game on a high.

AT A GLANCE

WAIKATO CHIEFS 48 (James Lowe 2, Toni Pulu, Tom Sanders, Brad Weber, Damian McKenzie tries; Damian McKenzie 3 conversions, 4 penalties) bt ACT BRUMBIES 23 (Scott Sio, Scott Fardy tries; Christian Lealiifano 3 penalties, 2 conversions) at Canberra Stadium on Saturday night. Referee: Angus Gardner. Crowd: 12,896.