But it is January and their success was for Auckland - not the Black Caps - and was at the Volts' expense.
Guptill whacked 108 from 114 delivieries and McClenaghan's opening spell accounted for three of Otago's top-order batsman.
Craig Cachopa also played a major role in helping Auckland post a challenging 344. He has been in punishing form and pummelled 110 from 100 deliveries on a batter-friendly surface at Eden Park Outer Oval.
He combined with Guptill in a damaging 202-run partnership - the 200 came up off 184 deliveries.
Otago's chase unravelled almost immediately as McClenaghan removed Aaron Redmond and Michael Bracewell in his opening over. He also bowled Derek de Boorder and returned later to claim Sam Blakely's wicket. The Volts' innings ended at 247 for nine - a 97-run loss - with Bradley Scott unable to bat.
The veteran left-armer was struck in the face by the ball during his final over and was immediately taken to hospital. The blow knocked out ''a couple'' of teeth but he is otherwise fine, Otago coach Dimitri Mascarenhas said.
McClenaghan's spell tore a large chunk out of the Otago batting stocks. While Sam Wells resisted with 47, and Iain Robertson played nicely for his 74, there really was no way back into the game, Mascarenhas said.
''[McClenaghan] is a good one-day bowler who has played a lot for New Zealand now and he has a good record,'' he said.
''He is a wicket-taker and one that we needed to really knuckle down to and not give our wickets away. But unfortunately he knocked over three of our top order and it was always going to be tough from there.''
Mascarenhas was not too disappointed with his side's effort in the field despite giving up nearly 350 runs.
''Two quality players got themselves in on a flat wicket and they got hundreds. That is what you've got to do in this format and that is why they won the game.''
Guptill posted his second century in three games and passed 5000 runs during the innings, while Cachopa took his season tally to 231 runs from just three games.
It was not all bad news for Otago. Pace bowler Jacob Duffy claimed his maiden five-wicket bag. He struck two early blows for Otago, removing opener Anaru Kitchen and the experienced Rob Nicol. He returned to bowl at the death, taking three wickets in the last over of the innings to finish with five for 58.
With Redmond, Bracewell and de Boorder all falling victim to McClenaghan, Nathan McCullum arguably represented Otago's last chance. He helped rescue the Volts' innings with a maiden century in the 16-run win against Wellington on Tuesday but could not repeat that performance.
He got a start but on 21 got an edge.
Wells and Robertson helped save Otago some blushes, and Duffy (39) and Sam Blakely (27) played useful cameos. In the day's other match, Central Districts posted a massive 405 for six in Timaru with opener George Worker clobbering 194 from 145 deliveries.
Canterbury replied with 353 - enough to win a match almost anywhere but not at Aorangi Oval. The venue has been a graveyard for bowlers over the years.
Otago A lost to Central Districts A by 13-runs in a men's provincial A one-day match at Lincoln yesterday.
