New Zealand never looked back after skipper Kane Williamson won the toss and sent Sri Lanka in to bat in the World Cup group game against Sri Lanka in Cardiff.
The bowlers did their job as they bundled out Sri Lanka for 136 before openers Martin Guptill and Colin Munro both scored fifties to help them clinch a convincing 10-wicket win.
Fourth in the ICC ODI rankings, New Zealand, registered a comprehensive six-wicket win over India before losing to a batting-heavy Windies by 91 runs in a World Cup warm-up.
Since the last World Cup, New Zealand have risen as high as second in the world rankings but have also been beaten at home by South Africa, England and India.
On the other hand, Sri Lanka have had a more chaotic build-up to the tournament and have lost 41 of the 55 ODIs played since the start of 2017.
New Zealand (Playing XI): Martin Guptill, Colin Munro, Kane Williamson(c), Tom Latham(w), Ross Taylor, James Neesham, Colin de Grandhomme, Mitchell Santner, Lockie Ferguson, Matt Henry, Trent Boult
Sri Lanka (Playing XI): Dimuth Karunaratne(c), Lahiru Thirimanne, Kusal Perera(w), Kusal Mendis, Angelo Mathews, Dhananjaya de Silva, Thisara Perera, Jeevan Mendis, Suranga Lakmal, Isuru Udana, Lasith Malinga