The Firebirds will play Otago at the University of Otago Oval on Saturday, with the winner claiming the crown.
Former Volts all-rounder Jimmy Neesham guided Wellington to victory with an unbeaten 120 from 107 deliveries.
He scored his maiden one-day hundred against the Volts in Dunedin earlier this month and told the Otago Daily Times his ideal scenario was to play Otago in the final and lead his new team to victory.
He will now get that opportunity thanks to his fine knock. Neesham clouted 12 fours and five sixes and has found some brilliant form with the bat this season.
Dunedin-born Ollie Newton also played a major role with a stunning bowling effort. The former Albion right-arm seamer took five for 47 to set up the win. Among his victims was the dangerous Colin Munro. The Black Cap is one of the most destructive ball-strikers in the game but got an outside edge to a cracking delivery and had to depart for 16.
Auckland slumped to 58 for five but rallied to reach 236. Graeme Beghin top-scored with 69 and featured in a 115-run stand for the sixth wicket with Robbie O’Donnell (54).
Wellington’s chase faltered early with both openers getting out cheaply. But talented left-hander Devon Conway (42) and former Otago player Michael Bracewell (41) helped get the innings back on track.
There was a flurry of late wickets but Neesham finished the innings in style with a six to seal the win.
Wellington will have to start as favourite in the final, despite having to travel south for the game. It beat Otago by 193 runs earlier in the tournament and had a narrow loss in Dunedin, when it appeared to have had the chase under control.
