The Irish duo had eight birdies to finish the third round with 8-under-par 64, and a 21-under total of 195 at the Mission Hills complex.
The United States, Germany and South Africa are tied for second at 197.
Martin Kaymer and Alex Cekja made 11 birdies in their 61.
Germany’s feat was matched by South Africans Charl Schwartzel and Louis Oosthuizen, who also managed 61.
The U.S. team of Gary Woodland and Matt Kuchar had 10 birdies and one bogey in a 63.
Today’s final round of the $7.5 tournament will see a return to the alternate shot format.
The World Cup features 28 teams.
SOUTH AFRICAN OPEN: In Johannesburg, South Africa’s Hennie Otto shot 7-under-par 65 and took a three-shot lead after three rounds.
Otto had seven birdies and an eagle, leaving him at 14-under on Jack Nicklaus-designed the Serengeti course.
He is followed by four players: Retief Goosen, Magnus Carlsson, Thomas Aiken and Garth Mulroy.
Otto is bidding for his second European Tour title and first since the 2008 Italian Open.
“I haven’t won it yet,” he said. “It’s a new day tomorrow.”
Otto has appeared calmer on the course of late after once throwing his clubs into a river during a tournament on the local Sunshine Tour.
“I’m not a guy who gets all nervous,” he said. “Maybe angry, not nervous.”
Goosen, two-time South African Open winner, shot 71 in a round marked by birdies on the first three holes.
AUSTRALIAN PGA: In Coolum, K.T. Kim played steadily over the back nine while other challengersfaded, shooting a bogey-free 5-under-par 67 to take a one-stroke lead over Bubba Watson into the final round.
Kim, who played for the losing International side at the Presidents Cup at Royal Melbourne last week, had a 54-hole total of 13-under 203 at the Hyatt Regency resort course.
Watson, who held the lead for part of the third round, double-bogeyed the par-5 15th to finish with 69.
Aaron Baddeley was in third place after 67, three strokes behind.
Despite winning his last two matches at the Presidents Cup, Kim said he wasn’t expecting a lot at Coolum.
“My expectations coming into this week were quite low,” the Korean said through an interpreter.
“Off the practice tee on Tuesday and then the pro-am on Wednesday, I sort of thought that this wasn’t my type of course. So I have over exceeded my expectations so far.”