Scotland scored 165 in 20 overs, led by Richie Berrington's 70, Matthew Cross's 45 off 36 balls, which included two sixes and two fours, and George Munsey's 15.
An entertaining knock down the order by Norman Vanua gave PNG fans some late hope. He and Kiplin Doriga added 53 off just 29 balls but having been 35/5 at that point in chase of a target of 166, PNG had left it too much too late.
Kabua Morea, PNG's top bowler, got four wickets for 31 runs in four overs, Chad Soper took three wickets for 24 runs in four overs, and Simon Atai grabbed one wicket.