Updated

By Mark Lamport-Stokes

AUGUSTA, Georgia (Reuters) - Back pain or not, there is something magical about Augusta National and the Masters for Fred Couples that keeps the easy-going American playing well enough to command the spotlight.

The 52-year-old from Seattle, who has limited his playing schedule in recent seasons due to lingering back injuries, fired a sparkling five-under-par 67 that surprised even himself on a tricky day for scoring in swirling breezes.

"For me to be tied at this moment, you know, it's a little shocking, but I played a really good round of golf today," Couples told a packed new conference at Augusta National after posting a five-under total of 139.

"I've not played that many rounds like this where it was cold and windy. There have been days where it's really blowing hard, but not that many.

"I just really, really enjoy playing here. I feel like I'm very young whenever I get here. I've said it for 28 years, this is my favorite golf tournament in the world. Can I win? I believe I can, yes."

Couples, who epitomizes 'California cool', is competing in his 28th Masters at Augusta National where he has recorded 11 top-10 finishes, most recently sixth place in 2010.

KNOWING AUGUSTA

"To play well here a lot I think is because I really know the golf course," the American said in typically laconic fashion.

"That doesn't mean I'm going to do well every single time, but I feel like I can get it around and figure out how to shoot a score on this course.

"I made a few putts, and ended up shooting a lot lower than I thought. Five under was an incredible round, a very, very good round."

Asked what it would take for him to become the oldest player to win the Masters, Couples replied: "A lot more birdies, a lot more good putts.

"And ATI blocker ... I'm on ATI blocker now," he added, referring to his back pain medication.

"I have to come out tomorrow, not be too edgy and hit a good tee shot on one. And if I have to make a five-footer for par on one, you've got to make a five-footer for par.

"And sometimes it doesn't go that way. It's a very, very difficult course. To be honest, I didn't know how the weather was supposed to be, but I certainly would like to see it warm up again."

The oldest man to win the Masters is 18-times major champion Jack Nicklaus, who was 46 when he won his sixth green jacket in 1986.

Couples, whose 1992 victory at Augusta National was warmly applauded for one of the most popular figures in the game, initially adopted a carefree strategy on Friday.

"Standing out there I say ���What the hell' a lot. ���What do I have to lose here? Go for the flag on this shot.' But once you really get cruising around, then it becomes play a smart shot," he said.

(Reporting by Mark Lamport-Stokes; Editing by Frank Pingue)