PNG defeated Hong Kong by 58 runs in the 4000th ODI.
Spin twins Lamichhane and Airee helped Nepal sweep aside PNG by six wickets in the play-off in Harare on Thursday.
A superb knock by West Indies skipper Jason Holder rides out a top-order wobble to make it two wins from two in the tournament.
India crushed Zimbabwe by 10 wickets in a Group B clash to maintain their all-win record at the ICC U-19 World Cup here on Friday.
After restricting Papua New Guinea to a well-below-par 95, a confident batting performance allowed Zimbabwe to canter to a 10-wicket win.
Scotland claim runner-up position; Hong Kong finish third and PNG qualify fourth.
One-Day International
