New Zealand skipper Kane Williamson hailed Pakistan and their swashbuckling opener Fakhar Zaman as "something special" for pulling off a 21-run win in a rain-hit World Cup duel on Saturday.

New Zealand had piled up 401-6 on the back of a third World Cup century from their young star Rachin Ravindra and 95 from fit-again Williamson.

But Pakistan, needing to win the match to avoid World Cup elimination, hit back in a blistering display of power hitting.

Zaman clubbed an 81-ball 126 not out spiced with 11 towering sixes and eight boundaries for an 11th one-day international century while captain Babar Azam made an undefeated 63-ball 66.

Pakistan were 200-1 in 25.3 overs -- after being set a revised target of 342 in 41 overs due to rain -- before the match was called off.

They had edged ahead by 21 runs on the DLS method at that stage.

"We saw something special today from Pakistan," said Williamson whose team have now lost four games in a row after starting the tournament with four wins.

"When Zaman's going, not many grounds are big enough and certainly this wasn't. He just hit it to all parts. So credit to the way Pakistan came out and achieved what they did today."

Before Saturday, only two teams had ever scored 400 in an ODI and lost.

Australia scored 434-4 against South Africa in Johannesburg in 2006 before the Proteas made 438-9 to win by one wicket.

In 2009 at Rajkot, Sri Lanka made 411-8, just failing to catch India's 414-7.

"The first half was, I thought, a great effort as we put up a competitive total," added Williamson.

"The guys in the second half tried hard but it was tough, the weather perhaps didn't help, but we can't take anything away from what Pakistan had to try and achieve and they came out and played beautifully."

New Zealand, equal on eight points with Pakistan from as many games, are still in a strong position to qualify for the semi-finals as they have a better net run-rate.

They meet Sri Lanka in their last group match, also in Bengaluru on November 9. Pakistan conclude against England in Kolkata next Saturday.

"I think the approach will be very similar. We can't rely on other teams as you get down to some small, small margins of whether it's run rate or your last match," said the New Zealand captain.

"Anything can happen really, but our focus is very much still on the cricket that we want to keep playing and adjusting to what's in front of us. And we've done that in really positive ways.

Williamson said he was happy to be back from a thumb injury sustained in the game against Bangladesh after also recovering from a knee injury ahead of the World Cup.

"It's just nice to be back out there, to be honest. Like playing the previous match and getting through that, with the focus being on my knee a little bit.

"Then to just break your thumb, which was a bit of a bummer. But, so just nice to be back out there with the team and playing."