In reply, Kieron Pollard-led West Indies kept losing wickets at regular intervals and could only reach 166/9 in 20 overs.
Earlier in the day, West Indies won the toss and opted to bowl first.
New Zealand opener Tim Seifert (18 off 13) was dismissed in the 6th over after a short cameo when he tried to be cheeky against Oshane Thomas. Martin Guptill (34 off 23) was also dismissed in the next over and West Indies appeared to have taken control of proceedings.
Conway and Phillips looked in good touch, however, taking time to get their eye in before lashing out. Both were on 15 at just over run-a-ball at the halfway stage of the innings before they started giving charge.
Phillips hit a six and back-to-back fours off Keemo Paul’s second over to push New Zealand’s total over 100. Two overs later, he clubbed Fabian Allen for a hat-trick of sixes in a 24-run over and the team run-rate soared to over 10 runs per over.
The rain-break shortly after had no effect on the momentum Conway and Phillips had gathered. The two consolidated until the final four overs before the carnage unfolded, with 47 runs taken off the 17th and 18th over combined.
Phillips raced to a 46-ball century, the 10th fastest in the world and one ball faster than the previous New Zealand record held by Colin Munro while Devon Conway completed a maiden T20I fifty (65 not out off 37).
The duo added put on 184 for the third wicket and took New Zealand to 238/3 in 20 overs. (UNI)