They beat the previously undefeated Ireland team.
Assad Vala and Norman Vanua were the heroes for PNG, keeping the team in the hunt for runs.
Ireland’s William Porterfield hit an unbeaten 57 as the Irish struggled to a modest 123-9 from their 20 overs at Stormont.
Norman Vanua's unbeaten 28 from 10 balls, including three sixes in the 19th over, took Papua New Guinea to 124-8 with seven balls to spare.
Ireland lost their 100% record but remain Group A leaders, a point ahead of second-placed Papua New Guinea.
The Irish innings was built on captain Porterfield's patient knock with Gary Wilson (10) and Alex Cusack (13 not out) the only other players to reach double figures.
They slipped to 33-4 after losing Niall O'Brien (nine) and Paul Stirling (one) early but Porterfield hit 57 from 58 deliveries to give them hope.
Kevin O'Brien continued his good form, claiming 2-11 after taking 3-8 in Monday's win over Nepal, while Tyrone Kane (3-19) and John Mooney (2-38) were also among the wickets.
Assad Vala had top scored with 32 before Papua New Guinea slumped to 93-8, at which point they needed 31 from the final 19 balls.
And with 20 required from the last two overs, Vanua smashed Mooney for those three sixes to win the game for his side.