Guptill compiled a gritty century in the first ODI in Napier, and on Saturday, 16 February, he built on that at the Hagley Oval, scoring a fluent 88-ball 118 to help his team close out the series with a game to spare.
In both games, New Zealand's bowlers kept Bangladesh to modest scores, well within the 250-mark. And each time, Guptill gave the visitors with no hope of bouncing back with the ball.
Bowlers, @Martyguptill star in New Zealand's series-clinching win!— ICC (@ICC) February 16, 2019
The hosts chase down Bangladesh's 226 by eight wickets in the second ODI at the Hagley Oval.#NZvBAN REPORT 🔽https://t.co/Uz6NRa0Rn8 pic.twitter.com/2B5RARzZH5
This wasn't the first time Guptill has scored consecutive centuries. He's done it twice before, including at the ICC Men's Cricket World Cup 2015 when he followed up his 105 against Bangladesh with an unbeaten 237 against the Windies. Before that, he did it during an ODI series in England in 2013. That stat hasn't gone unnoticed.
"Today, and in the last game, there were a couple of nice performances, obviously led by Martin Guptill," said Williamson. "He was brilliant, dominant, certainly in this game in terms of taking the momentum from the previous game. The number of back-to-back hundreds he scores is freakish."
It was also Guptill's 16th ODI ton, drawing him level with Nathan Astle at No.2 among centurions for New Zealand. Only Ross Taylor, with 20 to his name, has scored more.
"You always go out there and do your best for the team, and those milestones come about as by product of that," said Guptill.
Apart from Guptill's batting, another big positive for New Zealand was in the performance of their bowlers. "I thought the lads in the first half with the ball were outstanding," said Williamson. "There was a little bit there for us with the overcast conditions, and we did get a bit out of the surface. (It) allowed us to take regular wickets, which is important."
For Bangladesh, the only noteworthy performances came from Mohammad Mithun (57) and Mustafizur Rahman (2/42). Mashrafe Mortaza, their captain, urged the team to regroup and deliver a better result in the third ODI in Dunedin.
Bangladesh are all out for 226!— ICC (@ICC) February 16, 2019
Mohammad Mithun's half-century and Sabbir Rahman's 43 help the visitors bounce back from 93/5 to set New Zealand 227 to win.
How will the hosts fare in the chase? #NZvBAN LIVE 👇https://t.co/7VLP5qkjs8 pic.twitter.com/msVnY19hLt
"Mithun keeps scoring the runs, that's a good sign obviously," said Mortaza. "I think our top order has to step up a bit, but there are some positives – Mustafizur bowled well with the new ball today.
"We have to play as a group. Both matches we have scored 220-230. If we can score 270-280, we can fight it out. We had some partnerships but they were very short. We have lost the series, but there's a match left. Hopefully, we will step up and give it our best."