McDowell and McIlroy are 18-under through two rounds.
SHENZHEN, China (AP) -- Graeme McDowell and Rory McIlroy held onto Ireland's three-stroke lead in the World Cup of Golf on Friday, shooting a four-under par 68 in the second round.
The Irishmen were 18-under 126 for 36 holes after the alternate-shot second day of the $5.5 million tournament. Defending champion Sweden was second after Robert Karlsson and Henrik Stenson shot the day's best round -- a 7-under 65 -- at the Mission Hills Golf Club.
Italy (66) was four strokes off the lead in third, while Japan (71) was in fourth at 11-under. The American duo of Nick Watney and John Merrick was tied for 20th at 5-under.
"We are both playing really well and will be playing aggressively in the third round, looking for loads of birdies and eagles and trying to break 60 again," McDowell said.
Stenson said the 7,251-yard course suits the Swedish team's style of play.
"Robert did great and I think the way the course played, we had a different thought when we started the tournament last year on Thursday that I was going to hit on the odd holes, but then we spoke and came up with me hitting on the even ones instead," he said. "Robert drives the ball really nice and I've been hitting some good iron shots, and today we made some putts, as well."
Wales (68) and Venezuela (67) were both eight strokes off the lead, while four teams -- South Africa (70), England (69), India (68) and New Zealand (68) -- finished with a 9-under 135 for 36 holes.