* Defending champion Garcia slips back with a 70 (Updates at end of round)
By Andrew Both
GREENSBORO, North Carolina, Aug 16 (Reuters) - PGA Tour rookie Patrick Reed has not yet established himself on the U.S. circuit but that could change soon if he continues his current form.
Hot on the heels of two high finishes in his last two starts, Reed maintained his sizzling run to earn a one-stroke lead after the second round of the $5.3 million Wyndham Championship on Friday.
"We've been working extremely hard trying to fine-tune everything," the 23-year-old told reporters after shooting a bogey-free, six-under-par 64 on a calm, mild morning at Sedgefield Country Club.
"And lately with how I've been hitting the ball and how I've been putting, it just seems to all be clicking."
Reed posted an 11-under 129 total to finish a stroke in front of another young gun, fellow American John Huh, who fired the day's best score with an eight-birdie 62.
Compatriot Jordan Spieth (66) was another shot back at nine under, suggesting that the future of American golf is in good hands with all three front-runners aged 23 or less.
Defending champion Sergio Garcia, among a large group in joint third place overnight, shot a level-par 70 to slip six strokes off the pace.
Reed made his first cut on the PGA Tour here two years ago, but he has his sights set far higher this week after finishing seventh and ninth in his last two starts.
"I just need to put four rounds together and hopefully that's this week," said Reed, whose wife, Justine, serves as his caddie.
"She knows just as much about the golf swing, why I hit it left or right or anything like that, so if I ever get out of whack she can fix me immediately."
Huh, the 2012 PGA Tour rookie of the year, was by no means shocked after shooting a 62, though he felt a 64 was more likely when he teed off.
"I was able to put everything together and I'm really pleased," said Huh, who was born in New York of Korean parents and spent several years of his childhood living in South Korea.
He says he has been playing well since changing his driver shortly before the Masters, but had not put every component of his game together in the same round until Friday.
Garcia, meanwhile, lamented a cold putter, not for the first time in his career, after missing five putts from inside seven feet to fall six strokes off the pace.
"I would have loved to shoot at least a couple under (par) today. I feel I played well enough to do it but I didn't," the Spaniard said. "I wasn't able to hole it as well as yesterday from four, five, six feet."
The cut fell at one-under 139 and among those to miss out were former major winners Ben Curtis, Stewart Cink, Lucas Glover, Davis Love III, Mike Weir, Vijay Singh and Padraig Harrington.
Saturday's third round will start at 7 a.m. local (1100 GMT), because officials are worried that predicted rain will leave the course unplayable later in the day. (Editing by Mark Lamport-Stokes)