Brumbies winger Henry Speight crossed against the run of play, breaking through the Force's defence to open the scoring after 14 minutes.
While his goalkicking was wayward, Brumbies fullback Wharenui Hawera's fancy footwork was superb, helping him to score his first Super Rugby try to give the Brumbies a 10-0 lead.
The Force hit back on right on halftime with a well-worked rolling maul allowing Heath Tessman to go in for a try.
Jono Lance converted to bring them within three points at the break and the West Australians picked up where they left off in the second half.
A sweeping long ball from Ross Haylett-Petty found Peni in an acre of space to take the ball over for a try.
After missing his first three kicks, the decision to let Hawera go for a penalty goal was met with boos from the home crowd, but he silenced the doubters to narrow the deficit to one point.
The visitors temporarily arrested the Brumbies' charge with a penalty goal but the home side doubled down in search of their first win of the year.
Hawera's footwork created an opportunity for Kyle Godwin to score his first try for the Brumbies against his former club and the five-eighth kicked truly, taking the Brumbies to a 20-17 lead.
The Brumbies' scrummaging was superb throughout the night and a rolling maul allowed Robbie Abel to put the icing on the cake with a try in the dying stages.
- AAP