Auckland must beat Otago in a sudden death playoff to make the Ford Trophy final after their qualifier against Central Districts was rained off yesterday.
Top-ranked CD went through to the final and will host it next Sunday after the match in New Plymouth was abandoned.
Central won the tossand elected to bowl first at Pukekura Park. They had Auckland on the ropes at 71-4, but the visitors fought back through Colin Munro (64) and new Black Cap Colin de Grandhomme (66).
Despite 4-46 from left-arm orthodox spinner Marty Kain, Auckland made their way through to 230 before being bowled out in the 47th over.
Central began their chase cautiously but after five overs, with 16-0 on the scoreboard, the heavens opened and didn't let up. The abandonment put CD through because they were the higher-ranked qualifiers through the round robin.
They could meet Auckland for the second time in a week, with the quirky finals format giving Auckland another life and they will meet Otago at Colin Maiden Park on Wednesday.
Otago beat Canterbury in a low-scoring affair at University Oval in Dunedin on the back of a stellar individual effort from young all-rounder Jimmy Neesham.
The big-hitting 21-year-old struck a valuable 21 from No8 as the home side were bowled out for only 172 in the 39th over.
Sam Wells top scored for the blue and golds with 41, while veteran Craig Cumming added a useful 25. Canterbury's Matt Henry was the pick of the bowlers with 3-46 from nine overs.
Canterbury appeared to be cruising to a spot in the grand final qualifier at 107-2, but crumbled to be all out for 160 in the 46th over, handing Otago an unlikely 12-run win.