Otago has secured a tense three-wicket win against Auckland in Lincoln today.
Otago restricted Auckland to 250 for nine and went passed the target with an over to spare.
It was the Volts fourth consecutive win in the competition and has cemented the side in the top two.
Northern Districts overhauled Canterbury's 307 for four at Hagley Oval to move into third place, while Wellington held on to pole position with a 58-run win against Central Districts in Lincoln.