Former Black Cap Neil Broom scored his third hundred of the campaign to help the Volts post a formidable 312 for seven at Queen's Park in Invercargill on Saturday.
Auckland had stumbled to 159 for eight in 34 overs when poor weather forced the players from the field. The Volts won by 125 runs on the Duckworth-Lewis.
While the size of the margin might have come as bit of a surprise, the Volts' win would not have shocked many.
Otago made a poor start to the campaign but has played some brilliant cricket in the past few weeks.
The turnaround is largely down to the form of some of its key individuals and none have been better than Broom.
The 32-year-old rewrote the Otago record books with his fine innings of 109. It was his seventh one-day hundred - his sixth for Otago - and he extended his season tally to 508 to break the Volts' record for most List A runs in a season, eclipsing the 455 runs England's Jonathan Trott scored during the 2005-06 tournament.
Outside of the Black Caps, he is arguably New Zealand's best batsman.
‘‘He has just carried on from what he has been doing all season for us, really,''
Otago coach Nathan King said,‘‘It all looks pretty effortless at the moment for him and he just keeps going about his business and getting the job done for us.''
Otago lost opener Anaru Kitchen to the second ball of the match but Broom combined with another in-form batsman, Michael Bracewell, in an Otago record stand of 158 for the second wicket.
By the time Bracewell was eventually out for 69 from 75 deliveries, Otago had seized control of the match.
Jimmy Neesham helped capitalise with 59 from 54 and Derek de Boorder played a nice cameo with 24 not out from 14 balls at the death.
But Broom set the benchmark with his superb innings.
Auckland's attack suffered a setback when promising quick bowler Lockie Ferguson pulled up lame after just four overs.
Leg-spinner Tarun Nethula was demanding with one for 40 from 10 overs but the rest of the bowling unit struggled. Michael Bates went for more than eight an over and Colin de Grandhomme's 10 overs cost 71 runs.
‘‘ By the time we had posted 312 ... we'd done the first part of the job really well and had put immediate pressure back on the opposition,'' King said.
Jacob Duffy then bowled a cracking spell of three for 16 from six overs, removing both openers and the dangerous Mark Chapman.
Rob Nicol perished on 23, as his side slumped to 80 for five.
Robbie O'Donnell (37) and Shawn Hicks (31) added a modicum of respectability before the rain intervened.
While Otago was trouncing Auckland, it appeared as if Canterbury was doing the same to Central Districts at Hagley Oval.
But the defending champion rallied through a record-breaking 163-run partnership for the seventh wicket between Jesse Ryder and Ben Wheeler.
They beat the unbeaten 130 set by Wellington's Matthew Bell and Stephen Mather, against Northern Districts at Mount Maunganui in 1997-98.
Ryder was trapped lbw on 136 - his highest score - and Wheeler helped complete the two-wicket win with an unbeaten innings of 80.
Central will host the final at Pukekura Park in New Plymouth on January 30, against the winner of the Otago and Canterbury game on Wednesday.
Broom's run
At a glance
• Otago batsman Neil Broom's marvellous run of form continued during the weekend with a fine knock of 109 against Auckland in Invercargill.
• It was his third century in the campaign and he rewrote the history books in the process.
• It was his seventh one-day 100 and sixth for Otago, which is a record for the province.
• He extended his season tally to 508 runs, eclipsing the Otago record for most one-day runs in a season of 455 runs, scored by Jonathan Trott in 2005-06.
• Broom combined with Michael Bracewell in an Otago record second-wicket stand of 158. The previous mark of 155 was scored by Bracewell and Aaron Redmond, against Wellington in Wellington in 2013-14.
• Broom is the tournament's leading scorer with 508 runs at an average of 84.66 and strike rate of 91.03.
