Boult (3/20) rocked the Sri Lankan top order before Neesham (3/22) sent the lower order packing as New Zealand pacers produced a brilliant performance to put their side on a strong position.
Put into bat, Sri Lanka slumped to 35 for three in the sixth over with Boult producing a brilliant pace-bowling spell and they never recovered from there on in the virtual knock-out Group 1 match at the Zahur Ahmed Chowdhury Stadium.
There was a brief resistance from the Sri Lankans with Mahela Jayawardene (25) and Lahiru Thirimanne (20) adding 30 runs for the fourth wicket but they again slumped to a batting collapse.
Jayawardene was out in the 15th over as Sri Lanka were reduced to 85 for 6 and by then it was all over for them. Thisara Perera (16) and Sachithra Senanayake (17) made some contribution to take Sri Lankan score to 119 all out in 19.2 overs.