The Western Force have snapped a 14-match losing streak against the Brumbies with a 34-19 triumph over the "little puppies" at HBF Park.

The Brumbies entered Saturday night's match missing Wallabies stars James Slipper, Lachlan Lonergan, Allan Alaalatoa, Nick Frost, Rob Valetini, Nic White, Len Ikitau and Tom Wright as part of Rugby Australia's World Cup resting policy.

In the lead-up to the match, Force hooker Folau Fainga'a said the mass changes meant the Brumbies were sending over the "little puppies" to allow the "big dogs" to rest at home and get their necks massaged.

The Force raced out to a 21-0 lead inside 25 minutes, then weathered a Brumbies fightback before going on to secure the four-tries-to-three victory.

The triumph was the Force's first win over the Brumbies since 2013.

More importantly, the Force's fifth straight win at home this season ensured they ended the round in eighth spot, three points ahead of the ninth-placed Highlanders.

The Force finish their campaign with games against the Rebels (away) and ladder-leading Chiefs (home), and one more win might be enough to secure a finals berth.

But Saturday night's win came at a big cost, with Wallabies prop Tom Robertson injuring his left knee in the 51st minute.

Robertson was on crutches at the end of the match.

"I'm unclear right now on (exactly) what it is," Force coach Simon Cron said of the injury.

"They will take the time to do the scans, just check everything out with him.

"He's a beautiful man. We love him, he's a big part of our team, and we want him to get well as quick as he can."

Force playmaker Max Burey played an influential role in the win, nailing all four of his conversion attempts as well as two penalties in a perfect kicking display.

The Force made a blistering start to the match with tries to Felix Kalapu, Hamish Stewart and Sam Spink.

The Brumbies had their first try of the night in the 28th minute when flanker Charlie Cale got on the end of a sizzling fast break.

And it was game on when Wallabies lock Darcy Swain touched down in the 34th minute, reducing the halftime margin to nine points.

Fainga'a had fun against his former Brumbies teammates in the first half.

After stealing a wayward line-out and booting it forward to find touch, Fainga'a raised his hand in a celebratory gesture.

He couldn't help but have a laugh after stealing another line-out shortly before the break.

The Brumbies dominated long periods of the second half, but their only reward was a 53rd-minute try to Luke Reimer.

The Force defended their five-point lead for long stretches, and their determination was rewarded in the 70th minute when a series of pick-and-goes near the line resulted in a try to Marley Pearce.

Force playmaker Max Burey nailed the sideline conversion, and he repeated the dose with a 74th-minute penalty to seal the win.

"Very inconsistent across the board," Brumbies coach Stephen Larkham said of his team's performance.

"I don't think there was an area we were better than the Force tonight.

"We just made a lot of mistakes, whether it was set piece mistakes or individual mistakes that stopped us getting momentum."