Rory McIlroy racked up a double bogey six on the treacherous 18th but still made the cut with a shot to spare in the Verizon Heritage at Harbour Town Golf Links.

The world No 17 began the day nine strokes off the pace on one-over par but picked up two birdies and a bogey around the tight Hilton Head course before throwing all his hard work away at the 452-yard finishing hole.

Faced with a 188-yard approach, McIlroy finished in the water guarding the green, pitched to 25 feet and then holed a testing four and a half footer for a level par 71.

Rory McIlroyThat left him ten strokes behind leader Brian Gay (66) on one-over par and just inside the two-over par cut mark in a 17-man logjam for 48th place with the likes of Paul Casey and Luke Donald, who both carded 70s.

Playing in just his sixth PGA Tour event, McIlroy hit 50 percent of the fairways on the tactically demanding South Carolina Course as Gay opened up a one-stroke lead over 2004 Open champion Todd Hamilton, who is facing a battle to retain his PGA Tour card as his five-year exemption for winning the Open at Troon runs out this year. 

The American recorded his first top-20 finish of the season when he tied for 15th at The Masters last week and was pleased to card a bogey-free 66 that gave him the early clubhouse lead at eight under.

"I was allowed a five-year exemption for winning The Open in '04 and this is the final year for that," Hamilton said. "So I need to do something.

"I felt like this was going to be a good year. And getting off to a slow start, I think that's when I started thinking, man, you better start doing something and not waste your opportunity.

"You've got one year of a free pass left, you better start getting after it."