Whiddett's win on the weekend, his second in as many rounds, was worth 104 points - closing the gap between he and Woolhouse from 53 points to 28.5. Andrew Redward is another 6.5 points back in third, setting the scene for an all-action final in Auckland next weekend.
Earlier in the weekend, Whiddett was beaten by eventual second-place getter Cody Collis in qualifying to finish fifth.
After edging out Whiddett, Collis battled his way past Robee Nelson, Chris Jackson and V8 Supercar ace Shane Van Gisbergen before meeting and beating Tauranga driver Drew to guarantee himself a spot alongside Whiddett in the final.
However, just when it looked like the ultimate upset was on the cards, the Christchurch driver was forced to forfeit his last run thanks to an electrical problem which handed the win to Whiddett.
As well as winning the round outright, "Mad Mike" Whiddett also sealed victory in the three-round BP Ultimate Triple Crown series-within-a-series at Ruapuna Park, winning a year's worth of BP Ultimate 98 octane petrol.
Woolhouse and fellow Whangarei drifter Gaz Whiter finished second and sixth in the BP Ultimate series, with Woolhouse an agonising nine points shy of the prize.
D1NZ Series
Points after round five of six:
Daniel 'Fanga Dan' Woolhouse, 426 points, 1; 'Mad Mike' Whiddett, 397.5, 2; Andrew Redward, 391, 3; Curt Whittaker, 354.5, 4; Nico Reid, 308, 5; Daynom Templeman, 305, 6.