Guptill remained unbeaten on 117 as New Zealand chased down Bangladesh's 232 with 33 balls to spare. However, Guptill said that run-making wasn't as easy as it may have seemed.
"It was slow and we had to work hard on it," he said of the surface. "We were able to get through the first 10 overs without losing a wicket, and then push on for a big partnership that set up the game."
Both Guptill and his opening partner Henry Nicholls were circumspect early in their innings, scoring at less than five an over in their partnership of 103. But the stand helped the other batsmen take their time in the pursuit of a middling target.
"Bangladesh bowled really well in the first 10 overs. They didn't give a lot of bad balls away," Guptill said. "We had to work hard for our runs. The way Henry and I rotated the strike, I thought, it helped the partnership develop."
McLean Park in Napier is an east-west facing ground, and there was the issue of sun strike as well. The first ODI between New Zealand and India, which was the last 50-over match played at this venue, had to be stopped for a while in the second innings because the sun was in the eyes of the batsmen and the wicket-keeper.
New Zealand win the first ODI by eight wickets!— ICC (@ICC) February 13, 2019
Martin Guptill's unbeaten 117 and a fifty from Henry Nicholls help the hosts chase down Bangladesh's 232 with ease.#NZvBAN SCORECARD 👇https://t.co/HjcLR8C9cr pic.twitter.com/y4DJPT3wz7
Guptill admitted to facing a similar issue on Wednesday, although it was of a lesser magnitude.
"Today was good," he said. "We were able to push through a tough period. It wasn't easy to bat out there, with the sun coming down. But we were able to bat through that and make sure we set the platform. We also ensured it got easy for us towards the end.
"We just batted through, to be fair. I have batted at that time before. It is not much fun. But if you push on through, you can get through it. It was playable."