New Zealand's Trent Boult said Thursday "it doesn't get any bigger than taking on India in front of 1.5 billion people" as he counted down to their likely World Cup semi-final showdown in Mumbai.

Left-arm quick Boult returned figures of 3-37 to play a pivotal role in his team's five-wicket win over Sri Lanka that has virtually assured them a place in the last-four.

Rivals Pakistan and Afghanistan will have to pull off miraculous victories in their concluding group games in order to knock New Zealand out of the semi-final reckoning.

The Kiwis would face undefeated India in Mumbai next Wednesday with South Africa playing Australia in Kolkata 24 hours later.

"We're going to be very clear with how we're going to tackle that game," said veteran fast bowler Boult.

"I think there'll be a lot of excitement and the prospect of that challenge. It doesn't get any bigger than taking on India in front of 1.5 billion people."

New Zealand, who have been runners-up in the previous two World Cups, have an edge over India in tournament match-ups with a 5-4 advantage.

They knocked out much-fancied India in the semi-finals in 2019.

"I can't speak on what they're thinking but from our point of view to play a World Cup in India and to come up against the host nation, a team that's red hot and playing good cricket at a great ground, you couldn't script it any better," added 34-year-old Boult.

Rohit Sharma's India have been unbeaten to top the 10-team table.

India, who last won the World Cup in 2011, faced a stiff challenge from the Kiwis in their league match which they won by four wickets in Dharamsala.

Boult said the conditions at Mumbai's Wankhede Stadium will be different and the pressure will be on the hosts.

"Played India a lot of times. Quality players, know these conditions very well," said Boult.

"Hard to comment on what the conditions will be at Wankhede, but history suggests it's a good wicket.

"Very, very good players, but pressure does things to the best of players at any time."

Boult took three key wickets to rattle Sri Lanka after New Zealand elected to field first and bowled out the opposition for 171 in 46.4 overs.

With his first strike of skipper Kusal Mendis he reached 50 World Cup wickets to enter elite company including Glenn McGrath, Muttiah Muralitharan, Mitchell Starc, Lasith Malinga and Wasim Akram.

"Very proud, not something that I was ever targeting, but everyone loves World Cup cricket," said Boult.

"I've enjoyed playing with all the guys here. I've got very good friends in the team and we really help each other out. So nice to bring up 50 this afternoon and hopefully there will be a few more."