''We knew they've got world class players in their side so we had to scout well and come out and play well and we showed the one-day form we're in."
Just as New Zealand's unbeaten home record in tests now stands at 13 - seven wins, six draws - dating back to early 2012 and a defeat in Hamilton by South Africa, so too the ODI record is not to be sneezed at.
New Zealand have won their last 11 home ODIs, a record, their last loss coming in Wellington, as it happens against Sri Lanka last January.
Sri Lanka get another chance to show they are far better than the rabble of yesterday when the teams meet in the second of the five-game series, also at Hagley Oval tomorrow.
''We have to come out tomorrow and be on top of our game, like we were yesterday," Guptill said.
''(Tillekaratne) Dilshan is probably due a few runs and Angelo (captain Mathews) didn't have a great game, but they have very good players in their side."
The 39-year-old Dilshan is fourth on the list of ODI runscorers in this calendar year, a table topped by Guptill, while Mathews made his third first-ball duck as Sri Lankan captain, all against New Zealand.
- By David Leggat in Christchurch