He hit seven sixes and brought up the 50 with the winning runs with fully 60 balls to spare.
''To have a really tough match in that first game was important to us," Williamson said.
''It highlighted a few areas we want to improve on, but a lot of positives came out of that.
''To make those adjustments in this match and put in a complete performance is great for us as a T20 unit."
Williamson scotched any idea that more batting opportunities for the middle order would be beneficial.
''To win by nine wickets is a great effort and I'm certainly not looking at concerns about our middle order batters.
''You try to pick the best 15 (in a squad) for the moment and give every player freedom to go out and express themselves.
''You want to pick match winners. That's what we've looked to do. Certain guys in certain areas we see could benefit the team and cricket we want to play."
Never one to rest on his, or his team's achievements, Williamson added that ''those learning will need to be done again and again as we stick together and move through to other T20 matches.
''It's pretty fickle in nature and our feet are very much on the ground and we'll be looking to improve."
That road to March's world T20 in India will continue at Eden Park again on Friday night against Pakistan.
They arrive in Auckland today and New Zealand's squad for the three T20 games against them will be named around lunchtime today.
Pakistan will be without talented batsman Umar Akmal for Friday night's match as he has received a one-match ban for breaching the Pakistan board's code of conduct.
Akmal has been punished for failing to adhere to clothing guidelines relating to sponsors logos during last week's Quaid-e-Azam first class domestic final in Karachi between his team, Northern Gas Pipelines Ltd and United Bank Ltd.
Pakistan T20 squad: Shahid Afridi ©, Mohammad Hafeez, Ahmed Shehzad, Sarfraz Ahmed, Umar Akmal, Shoaib Malik, Saad Nasim, Mohammad Rizwan, Imad Wasim, Aamer Yamin, Shoaib Maqsood, Iftikar Ahmed, Anwar Ali, Umar Gul, Wahab Riaz, Mohammad Amir.