A trip to Canberra was the final test and it shaped as a stern examination given the Brumbies had won three of their last four meetings between the sides.
The Chiefs’ sole loss this season came against Australian opposition — stunned by the Reds earlier in the month — but Clayton McMillan’s side controlled this contest almost throughout.
Their All Blacks hopefuls all fired: an electric Emoni Narawa set up Shaun Stevenson for his 11th try of the season; Damian McKenzie still made his presence felt in a rare start at fullback; and Luke Jacobson was immense on both sides of the ball.
All the individual performances added up to a collective effort that ensured the Chiefs could rest up ahead of the quarter-finals, with next weekend’s trip to the Force the final tuneup before the playoffs.
There wouldn’t be all that much tuning required based on tonight’s display, as the Chiefs steadily built their lead in a manner that reflected the small but significant gap between good sides and great.
While little separated the teams during general play, the key difference — and what would prove decisive — was the Chiefs’ competition-leading defence standing tall while their opponents were guilty of faltering at the wrong moment.
The Brumbies enjoyed plenty of positive moments with a fair share of possession, yet they pressure they built through phase play would regularly amount to nothing.
Along with the wall in white that repelled their advances, the Brumbies were undone by some costly turnovers, unable to execute the final pass to unlock their obdurate opponents.
The Chiefs, in contrast, taught the home side a clinical lesson, producing a couple of moments of quality to grab two first-half tries.
The first came during the opening exchanges as, with a scrum going nowhere 40m from the line, Jacobson broke down the blindside and sold a big dummy to charge across almost untouched.
The second exemplified the Brumbies’ issues in defence as Josh Ioane — swapping first-receiver duties well with McKenzie — slipped through a gaping hole to make it 17-7 at the break.
The hosts missed too many tackles throughout the half but one man who did not miss was Allan Alaalatoa, sent to the sin bin midway through the half for a high shot on Brodie Retallick and perhaps fortunate to return.
The Brumbies conceded only three points while their skipper was on the sidelines and remained in the contest through Len Ikitau’s try, but the Chiefs didn’t need long in the second spell to seal top spot.
As in the opening half, the Brumbies failed to turn an advantage in field position into points. And yet again, their frustration only grew as the Chiefs pounced when sniffing half a chance.
Cortez Ratima — introduced early after Brad Weber departed for an HIA — was particularly opportunistic as he picked off as loose pass from Connal McInerney to find himself with a clear path to the line.
Once Narawa had made the most of more good work from Jacobson to set up the newly introduced Stevenson, there was no way back for the Brumbies — and no catching the Chiefs on the standings.
Chiefs 31 (Luke Jacobson, Josh Ioane, Cortez Ratima, Shaun Stevenson tries; Damon McKenzie 4 cons, pen)
Brumbies 21 (Len Ikitau, Corey Toole, Pete Samu tries; Noah Lolesio con, Jack Debreczeni 2 cons)
Halftime: 17-7