ND lead Auckland by 15 points, with 20 on offer in each game. ND had figured six wins would do the job. They've got four and are away to Central Districts in the final round.
ND would prefer to wrap up the title next week rather than have it all hinge on the final round.
"We have huge respect for Auckland's fighting qualities and the Plunket Shield is nowhere near over," Bradburn said.
He is clear on what's been the most important factor in ND's strong first-class campaign this season.
"The leadership of the senior players has been the core of the side, while we've had changes with Black Caps players coming and going. The younger players have come in and performed.
"The depth is there, but the leadership group has been the absolute key."
Auckland have retained the same 12 from the innings win over Otago last week, a victory notable for left-armer Mitchell McClenaghan's eight for 23 in Otago's first innings of 63, off-spinner Bhupinder Singh's impressive six for 60 in the second innings, and captain Gareth Hopkins scoring his second century in three innings.
In the other games, bottom side Otago host second-bottom Canterbury, while Wellington play CD at the new first-class venue of Karori Park.
Points after eight rounds: Northern Districts 89, Auckland 74, Wellington 71, Central Districts 69, Canterbury 50, Otago 37.
Plunket Shield
Ninth round
Auckland v Northern Districts
Colin Maiden Park, 10.30am
Auckland: Gareth Hopkins (c), Jeet Raval, Brad Cachopa, Neal Parlane, Anaru Kitchen, Colin de Grandhomme, Colin Munro, Mitchell McClenaghan, Bruce Martin, Michael Bates, Dean Bartlett, Bhupinder Singh.
ND: Brad Wilson (c), Daniel Flynn, Joey Yovich, Hamish Marshall, James Marshall, Anton Devcich, Peter McGlashan, Trent Boult, Tim Southee, James Baker, Joe Walker, Graeme Aldridge.