|Ireland (6) 6|
|Papua New Guinea (8) 14|
|Tries: Lo, MacDonald, W Boas|
|Goal: A Boas|
World Cup co-hosts Papua New Guinea took a major step towards reaching the quarter finals as Group C winners by beating Ireland 14-6 in Port Moresby.
Only one team will progress from the group to the play-offs, with England the likely opponents in the last eight.
Watson Boas scored two minutes from time to seal victory for the Kumuls.
Wigan hooker Michael McIlorum touched down for gritty Ireland in the first half, with Garry Lo and Nene McDonald scoring for PNG in a scrappy match.
PNG beat Wales 50-6 in their opening fixture and play the USA in their final group match next weekend.
Ireland beat Italy 36-12 in their first match and will complete their group games against Wales in Perth on 12 November.
Papua New Guinea held a two-point lead for 52 minutes before Boas pounced on a dropped pass in the Ireland backline, kicked through and won the race to the ball to score.
Ireland were impressive in the early stages with a strong wind at their back, McIlorum scoring the first try in the fifth minute after PNG captain David Meade failed to deal with Shannon McDonnell's lick into the in-goal area.
Papua New Guinea found the line twice and managed to head into the break with a slender two-point lead despite Rhyse Martin being unable to convert either try.
Winger Lo showed a turn of speed to beat several defenders to bring his side to within two points and then MacDonald made it 8-6 when he stepped inside Liam Key in the 26th minute.
PNG had eight line breaks in the first half but squandered a number of other scoring opportunities with poor handling and options in an error-strewn game.
Lo had a 42nd-minute try ruled out after his knee touched the dead-ball line.
With 10 minutes remaining, Ireland's Louie McCarthy-Scarsbrook knocked on over the line and seconds later at the other end Justin Olam had a try scrubbed for a forward pass.
Papua New Guinea: David Meade (capt), Justin Olam, Kato Ottio, Nene Macdonald, Garry Lo, Ase Boas, Watson Boas, Stanton Albert, Kurt Baptiste, Luke Page, Rhyse Martin, Willie Minoga, Paul Aiton.
Interchanges: James Segeyaro, Wellington Albert, Stargroth Amean, Enock Maki
Extended interchanges: Moses Meninga, Lachlan Lam, Nixon Putt, Wartovo Puara
Ireland: Scott Grix, Shannon McDonnell, Ed Chamberlain, Michael Morgan, Liam Kay, Api Pewharirangi, Liam Finn (capt), Brad Singleton, Michael McIllorum, Kyle Amor, Louie McCarthy-Scrasbrook, Oliver Roberts, George King.
Interchanges: Tyrone McCarthy, James Hasson, Joe Philbin, Anthony Mullaly
Extended interchanges: Will Hope, Joe Keyes, Matty Hadden, Jack Higginson