Wellington, Jan. 17 (AFP) - New Zealand sealed their T20 series against Pakistan with two games to spare Wednesday on the back of a record 137 off 62 balls by opener Finn Allen at University Oval in Dunedin.

The Black Caps, sent in to bat in game three of the five-match series, won by 45 runs after posting a colossal 224 for seven and restricting Pakistan to 179 for seven.

It followed their victories by 46 and 21 runs respectively in the first two matches.

The swashbuckling Allen, following on from his 74 off 41 balls in game two, frequently belted the ball out of the ground as he smashed 16 sixes and five fours in his whirlwind innings.

He said he has been working on trying to spend more time in the middle while still being explosive.

"It's a bit of both, you know, picking my moments when to go and picking bowlers too. For me, playing the ball on its merits and hitting it where it's supposed to go is kind of what I've been trying to do," he said.

Mitch Santner, standing in as New Zealand captain for the injured Kane Williamson, said the innings went as planned.

"The way he constructed his innings, we talked about trying to do it for as long as he can, and he did it for a long time today."

The opener's 137 is the highest score by a New Zealander in a T20 International, surpassing the previous best of 123 set by Brendon McCullum, and it equalled the world record of 16 sixes in an innings held by Afghanistan's Hazratullah Zazai.

He dominated the bowling, taking 27 off one over by Haris Rauf with three sixes, two fours and a single.

Rauf conceded 60 off his four overs while Mohammad Nawaz gave up 44 and Shaheen Afridi 43 on a dismal day with the ball for Pakistan.

After the early dismissal of Devon Conway for seven, Allen and Tim Seifert put on 125 for the second wicket, with Seifert only contributing 31 as he opted for singles to keep the hard-hitting opener on strike.

The umpires had to call for replacement balls three times, after Allen smacked missiles out of the ground.

The opener was eventually undone in the 18th over when he was bowled by an off-cutter from Zaman Khan, who then applauded the New Zealand batsman as he left the field.

In reply, Pakistan never looked like getting close to the required 11.25 run rate.

They reached 95 for two in the 11th over, but saw a clutch of wickets derail their chase, losing four for just 39 runs.

Babar Azam top-scored with 58 off 37 deliveries while Mohammad Nawaz contributed 28 off 15 in a late cameo.

The remaining two matches are in Christchurch on Friday and Sunday.