In Thursday's fourball 58 they didn't have a five on their card. But Rory McIlroy and Graeme McDowell showed they are somewhat human after all when they carded a six and a seven in a battling foursomes 68 and still remained three clear in the Omega Mission Hills World Cup.

The Ulstermen cruised five shots clear of the field after two birdies and an eagle on the front nine but stuttered on the way home before recovering brilliantly.

A wild McIlroy drive led to a bogey at the par five 11th and after a two at the "short" 13th they racked up an ugly double bogey seven at the 15th when McDowell found water with his approach and his partner missed a short putt of little more than two feet - the umpteenth error he has made form this distance over the past 12 months.

They bounced back, however, with birdies and the 16th and 17th to lead on 18-under-par. With Argentina taking 75, they are three ahead of Swedes Henrik Stenson and Robert Karlsson, the defending champions, who scorched into contention with a seven-under-par 65. Ominously for the Irish pair, it was the only bogey free round of the day.

"We started out the day with a three-shot lead and we still have a three-shot lead, it was a good day," McIlroy said. "This format is a lot trickier than the fourball, you have to rely on your partner to get you out of trouble, while you have to take responsibility in the fourball."

McDowell revealed that the back nine errors brought the pair back to reality but insisted that they were not looking at leaderboards and simply trying to "keep the foot on the accelerator" as much as possible.

"I think we would have taken 68 on the first tee," added McIlroy. "We had a goal which was to get a bit lower than that, but we played pretty solid and apart from the couple of mistakes on the back nine, we could have got a better score.

"I think we really showed good character to come back with the two birdies on 16 and 17 after the double bogey, it was a good days work."

McIlroy added that they would be trying to go "break 60 again" in Saturday's fourballs, explaining that "we left a few out there" in the first round 58.

Italian brothers Francesco and Edoardo Molinari are four shots off the pace in third after a 66 with Japan's Hiroyuki Fujita and Ryuji Imada (71) fourth at 11 under and Wales (68) and Venezuela (67) a further shot adrift.

England's Ian Poulter and Ross Fisher are nine behind after rounds of 66 and 69.