McKenzie kicks Chiefs to Super Rugby semi-final win over Brumbies
Both teams scored three tries in Hamilton but fly-half McKenzie landed eight shots from nine, including six penalty goals, in a 22-point haul as the Chiefs booked a place in next week's final against the Canterbury Crusaders.
The Crusaders beat the Auckland Blues 21-14 on Friday and are seeking their eighth title in nine seasons.
The Chiefs have not won the title since 2013, having lost in the final the past two seasons.
All Blacks sharpshooter McKenzie was at the heart of a clinical Chiefs display, setting up two tries and saving one when he held up Brumbies fullback Tony Wright over the line.
"Outstanding performance from the lads. Obviously the Brumbies came out of the blocks fast, like we knew they would, and I just loved the way we were really composed," the 30-year-old told Sky Sport.
"When we got in their 22 we managed to come away with points most of the time, so very pleasing."
The Brumbies lost Wallabies fly-half Noah Lolesio, who failed a head injury assessment in the opening minutes and was replaced by Jack Debreczeni.
They soon had a one-man advantage when Chiefs lock Tupou Vaa'i was shown a yellow card for a high tackle and capitalised with a try by hooker Billy Pollard from a lineout drive.
The Chiefs responded with a clever try by winger Emoni Narawa, who scampered through at the base of a ruck to score.
McKenzie converted and then landed all four of his penalty shots before the interval, with the Brumbies pushing too hard for turnovers at the breakdown.
The visitors scored a second try before the break when Debreczeni picked out winger Corey Toole with a cross kick to trail 19-12.
Toole crossed again through a fine solo try soon after the restart to close within two points.
Narawa bagged his second following a break from McKenzie, who kicked two more penalties and threw the last pass to put replacement back Josh Jacomb over for their final score.
"We had to play close to a perfect game to come over here and get the result," Brumbies captain Allan Alaalatoa said.
"We probably saw in the second half that our accuracy let us down and, off the back of that, probably our discipline as well."
Saturday's decider in Christchurch will be the fourth successive all-New Zealand final since Super Rugby Pacific launched in 2022.
The Brumbies have lost in the semi-finals in each of those seasons. No Australian team has won a play-off match in New Zealand in 21 attempts.