Williamson struck a second successive century to lead his side to 291/8 against West Indies.
West Indies made three changes as their captain Jason Holder won the toss and opted to bowl against New Zealand
In all likelihood, West Indies are one loss away from missing a semi-final berth.
With three losses, there is a slim chance left for West Indies to progress to the knockouts.
Chris Gayle has managed to score just 38 runs from four innings against New Zealand.
New Zealand won the first of the three T20Is by 47 runs. The final match will be played on January 3.
By virtue of the first T20I defeat, West Indies remain winless in their ongoing New Zealand tour.
The live telecast of the West Indies vs New Zealand 1st T20I will be available on Star Sports Select 1 and Star Sports Select 1 HD.
The live telecast of the WI vs NZ 3rd ODI will be available on Star Sports Select 1 and Star Sports Select 1 HD.
Beaton has so far played two ODIs for West Indies.