On the second run Mason matched Citroen's Mikko Hirvonen and American superstar Ken Block for the ninth quickest time.
Earlier in the event Dunedin's Emma Gilmour matched Mason's pace, the pair quickly breaking clear of the rest of the national championship field as well as running strongly in the overall order for the rally.
As Gilmour's car struggled for grip, she finished day one some 50s behind Mason, but on the second day, traded times all day to reduce the margin to just 12s on Saturday night. Gilmour set out on Sunday morning determined to take the leg win from Mason, but was severely hampered by a brake problem and a holed radiator.
Christchurch's Matt Jansen continued his excellent and consistent form to finish Brother Rally New Zealand a very strong third in the NZRC field.
In the overall results, Mason took a commendable 13th place overall - and second-best New Zealand finisher behind new Super 2000 World Rally Championship leader Hayden Paddon.
Gilmour secured her best-ever result of - 14th - in a WRC event, and Jansen took 15th overall.
All three leading NZRC competitors finished ahead of the winner of the Production World Rally Championship class, Argentinean driver Marcos Ligato who finished 16th in the same specification production or Group N four-wheel-drive machinery.
Another NZRC highlight came for Timaru's Chris West. Although challenged by mechanical issues during the weekend, the former champion made a last stage charge to win the power stage and claim an additional three championship bonus points. The Masons have an all but insurmountable lead in the five-round NZRC, taking their points tally to 138 points, 38 points ahead of Gilmour on 100.
"I've got to say we were struggling the first couple of days, especially on Friday night when they pulled the gearbox out and attempted repairs to the clutch, which didn't work," said Mason in after-race comments.
"Saturday night we got the clutch all going again and today (Sunday) we found driving comfortably brought the times to us. "There have been a lot of mentions from other competitors that our time around the Auckland Domain stage was incredible - especially from Petter Solberg."
Fourth after a consistent drive, Rangiora's Matt and Nicole Summerfield had their best result of the season to take the lead in the open 4WD class from Coromandel's Alex Kelsey, who led both the overall championship and open 4WD earlier in the season.
Nelson's Ben Hunt and co-driver Tony Rawstorn also performed consistently in their Ford Fiesta to take the lead in the Group N 2WD category title race. The pair finished fifth in the NZRC field and was the first 2WD crew home in the whole Brother Rally New Zealand field.
Hamilton's Miles McElwain has come within striking distance of winning the historic category trophy by finishing all three days and collecting maximum bonus points usually scooped by leader Marcus van Klink. Van Klink still leads the historic class with 126 points to McElwain's 104.
