Putting woes leave Tiger Woods six behind first-round leader John Peterson

North Carolina: Tiger Woods struggled to adjust to slow greens as he slipped six strokes behind American leader John Peterson in the opening round of the Wells Fargo Championship in North Carolina on Thursday.

On a day when two-times Wells Fargo winner Rory McIlroy started with a smooth three-under-par 68, Peterson made consecutive eagles for a sizzling 65 at Quail Hollow in Charlotte. Peterson, a former American collegiate champion, led a group of five players by two strokes, while Woods missed two putts from inside five feet en route to a 71.

Woods, a 79-times PGA Tour winner who needs three more wins to match Sam Snead`s all-time record, used a new set of irons but it was the flatstick that caused his problems. "I struggled with my speed all day," Woods said. "It`s weird. The greens are slow. They`re springy and firm. That`s not a combination you would expect. I struggled making the adjustments today."

Woods, healthy again after a spinal fusion more than a year ago, is playing his seventh tournament of the year. He said he was now in "playing shape" and the goal was "just trying to get a little better."

The 42-year-old and four-times major winner McIlroy are both making their first starts after disappointing performances at the U.S. Masters. Woods tied for 32nd at Augusta National, while McIlroy squandered a chance to complete the career grand slam after starting the final round in second place behind eventual champion Reed.

McIlroy says he licked his wounds for about a week after a final round 74 at the Masters, but is now trying to look forward rather than back. "I would have taken that score before I went out there," he said of his 68. 

"I struggled a little bit with my game in the pro-am yesterday. I did some practice yesterday afternoon which seemed to pay off. I could take it straight from the range onto the golf course this morning.

"I was a little apprehensive today. I didn`t know what to expect. I made some good swings and hit some good putts." The Northern Irishman clinched his first PGA Tour victory at Quail Hollow in 2010, while American Justin Thomas last August captured his first major on the same course.

Thomas made a mediocre return to the venue on Thursday with a two-over 73, while Masters champion Reed fared better with a 71.