England rises to second but India and South Africa drop following annual T20I rankings update.
PNG throws away excellent start to go from 54 for no loss to 128 for 5, which is overhauled with five balls to spare by the home side.
Home side takes series 2-1 after Papua New Guinea goes down by 103 runs in final game.
Side finishes second on WCL Championship table; UAE falls 26 runs short chasing 233 despite Ghulam Shabber fifty.
Batsmen combine to put up a healthy 292/5 and bowlers keep PNG to 210 all out in WCLC match.
Ireland registered an 8-wicket win over hosts UAE, in the second and final ODI in Dubai on Saturday.