Colin Munro's second fastest Twenty20 half-century for New Zealand further demonstrated his value as an opener in white-ball cricket, despite rain ruining the second match against the West Indies in Mt Maunganui.

The left-hander peppered the boundary at will, hitting 11 fours and three sixes in his 66 off 23 balls. The players exited with the Black Caps 102 for four from nine overs.

Munro also owns the fastest New Zealand T20 half-century, an unbeaten effort off 14 balls batting at No.3 against Sri Lanka at Eden Park two years ago.

The 30-year-old played with a fearlessness more suited across town at the beach. His power-hitting provided an antidote to any West Indies bowling venom.

The only fielders who stood a chance of snaring him were the one-hand catching brigade seeking a prize of $50,000 beyond the boundary. Each opportunity was cannibalised by greedy hands clambering to get-rich-quick.

As an opener in five T20 innings against India and West Indies, Munro has succeeded three times and failed twice, an acceptable ratio if fans are to accept the wonder of his attacking instincts.

His 109 not out off 58 balls in October's 40-run victory over India at Rajkot first illustrated his ability in the role; that was reinforced by 53 off 37 balls in the opening 47-run win over the West Indies on Friday. His strike rate as an opener is 183 as he employs the Neil Young Principle, preferring to burn out rather than fade away when he dons the pads.

Kane Williamson's contribution to Munro's cause was also valuable. He came to the wicket to face the fifth ball of the innings when Martin Guptill exited for two. That was the only dot ball the New Zealand captain faced in their 75-run, 25-ball second-wicket partnership. Williamson made eight off as many deliveries, working the strike to maximise Munro's resource.

Williamson looked comfortable in his return to internationals after a Christmas break. He was 17 not out from 15 balls when the New Zealand innings ended.

There was one exception; Williamson was subject to a stumping chance on 10 during the seventh over from off spinner Ashley Nurse. Replays showed him channelling a touch of Rudolf Nureyev with his right toe balanced precariously inside the popping crease when the bails were removed.

The significance of the night will not have been lost on the New Zealand captain with the contest held in his home city and the Bay Oval's recently-installed lights debuting in an international.

The Bay of Plenty cricket community helped raise $4 million to get the ground ready for day-night matches. $3.3 million was invested in the lights; the rest funded a replay screen, improved media facilities and an increase in the height of the ground embankment on one side, adding space for 2000 more patrons to take the capacity to 11,500. Their ultimate ambition is to host tests.

The flick of a few switches enabled their six new LED towers to bath the turf in lux suitable for any International Cricket Council fixture.

Unfortunately, they could only toast them by raising umbrellas. They get another chance on Wednesday when the ground hosts the final match of the T20 series, although the forecast is again grim.