Mujeeb ur Rahman was the star bowler on the day as he recorded a fantastic five-wicket haul while conceding only 20 runs in four overs.
Oman were bowled out for 122 in Muscat and Scotland eased home with three overs to spare after Kyle Coetzer made a timely return to form.
Scotland will guarantee a place in the T20 World Cup Super 12 if they beat Oman on Thursday.
The Scots had batted in the first innings and posted a score of 165-9 while PNG managed a score of 148 all out in 19.3 overs.
Chris Greaves was the star for Scotland as they defeated Bangladesh to cause a major upset in the ICC World T20 2021.
Scotland held their nerves to record a famous victory against Bangladesh, having been reduced to 53/6 in the first innings.