The Brumbies have claimed bragging rights over the NSW Waratahs, winning 27-20 in their Super Rugby Pacific showdown at Canberra Stadium.

The Brumbies have made it three straight wins to start the Super Rugby Pacific season, seeing off a dogged NSW Waratahs outfit for a 27-20 win.

The hosts came out breathing fire at Canberra Stadium and led 10-0 before they'd laid a single tackle, and steadied well when the Waratahs finally brought the challenge.

Having led 24-6, the Brumbies appeared to be cruising but the dynamic visitors just wouldn't quit, although they couldn't find a way over the line late when it mattered most.

With his side now 3-0 for the season and the last remaining unbeaten Australian team, Brumbies captain Allan Alaalatoa said they were building nicely.

"The emotion off the bench at the final whistle showed how important that win was," he told reporters.

"We wanted to start fast with a bit of rain about, so we wanted to play at the right ends of the field.

"We put together some great attacking phases there and gave ourselves some good opportunity.

"The most important thing is just taking it game by game, definitely celebrating this win and then moving forward."

The Brumbies were on the board within five minutes as their forward pack took control and allowed Rob Valetini to dive over and score.

The hosts kept their foot on the pedal and extended their leads when Noah Lolesio slotted a penalty on 13 minutes.

Finally looking to get a foothold in the match, Waratah No.10 Ben Donaldson pulled a mid-range penalty kick wide, although he popped one over from slightly closer on 22 minutes.

NSW flanker Charlie Gamble then looked on to score with a scintillating run from his own half, with only a desperate try-saving tackle from fullback Tom Banks preventing him.

The Waratahs reduced the deficit further with another penalty but the Brumbies struck back immediately through Nick Frost to go ahead 17-6, able to burst through the line after a brutal run from Valetini.

Irae Simone gave the Brumbies some breathing room with a highlight reel try, stepping around half the Waratahs team and scoring under the posts.

Donaldson broke through the line and found a surging Angus Bell to pull it back to 24-13 just before the hour.

Lolesio slotted a penalty but the Waratahs wouldn't go away, with a slashing run from Donaldson finding Will Harris in the corner, before the sideline conversion set up a tense final five minutes.

James Slipper was outstanding either side of a trip off the field for a HIA, while Valetini produced a string of heavy carries that drove the Brumbies forward at will.

For the Waratahs, Bell put in a shift up forward and Donaldson continued his rise as the chief playmaker, while Gamble made things happen with numerous dashing runs.

Coach Darren Coleman said his overriding emotion was pride after his side refused to quit.

"I'm really proud of my team ... obviously disappointed with the loss but we're trending the right way," he said.

"To come down against the Brumbies on their home ground in the wet, to get away with a losing bonus point and probably had the better of the last 20 and could even potentially say we we had a chance to draw it up or or do better."