New Zealand's three-pronged spin attack, however, ensured it was more than enough as Mitchell Santner (4-11), Nathan McCullum (2-15) and the Indian-born Ish Sodhi (3-18) wrecked the hosts who folded for 79 in 18.1 overs.
Williamson said it was not an easy decision to drop the pace duo of Tim Southee and Trent Boult to accommodate the spinners.
"Obviously that was tough, they are world class bowlers," the Kiwi captain said.
"But at the same time we are looking to do the best we can in these conditions. Certainly the spinners paid off today. The wicket spun a lot and they bowled very well on it."