As Soren Kjeldsen and Thorbjorn Olesen moved into a three-shot lead by firing a 12-under-par 60 in the fourballs, the Irish pair could only manage a 69.
The Irish started with a destructive bogey at the first and carded only four birdies, as they parred the last seven holes in Melbourne.
Combined with their opening foursomes 72, the Irish duo are sharing 16th.
Danish duo Kjeldsen and Olesen lead Chinese pair Wu Ashun and Li Haotong by three shots with Spain's Rafa Cabrera Bello and Jon Rahm a further stroke back.
The Chinese players shot a 65 on Friday with the Spaniards carding a 67.
English duo Chris Wood and Andy Sullivan are five off the pace after their 66 on Friday which left them in a share of fourth spot along with Italy, the USA and France.
Welsh pair Bradley Dredge are a stroke ahead of Ireland in 14th spot after carding a second-round 66 while Scotland appear out of contention, 11 off the pace, despite their 65 on Friday.
The Scottish pair of Russell Knox and Duncan Stewart propped up the field following a first-round 78 in the foursomes.
Ireland duo Graeme McDowell and Shane Lowry are nine behind leaders Denmark at the halfway stage of the World Cup.