Justin Rose fires 66 at Pebble amid buzz surrounding Justin Timberlake

PEBBLE BEACH, Calif. -- Justin Rose, a U.S. Open champion and the No. 7 player in the world, shot a 6-under 66 his first time playing Spyglass Hill and spent a gorgeous day listening to the fans call out his name. Except they weren't calling for him, and he knew it.

His partner in the AT&T Pebble Beach Pro-Am is Justin Timberlake.

"I've never seen a demographic like that on a golf course where you're sort of running the gauntlet from one tee to the other. Everyone was under 21 and 80 percent female," Rose said. "I said, 'OK, that moved the needle a little bit there.'"

Rose did OK himself Thursday.

He got off to a strong start is his debut at the Pebble Beach Pro-Am, where Chez Reavie had the low score at a tournament that needs three days to sort out because of the variety of courses.

Reavie made an eagle on the 16th hole and shot 8-under 63 at Monterey Peninsula, which played just more than 1 1/2 strokes under par and was the easiest of the three courses. Freddie Jacobson made five birdies in a six-hole stretch and shot 7-under 65 at Pebble Beach, the only course to play over par (72.06) on Thursday.

Cameron Smith of Australia and Bronson Burgoon each had a 7-under 64 at Monterey Peninsula.

Rose is among six players from the top 10 in the world, and the only one of them to break 70. This is his first time playing the Pebble Beach Pro-Am, partly because he chose not to play in the Middle East swing on the European Tour, and partly because of a partner (Timberlake) that he has come to know over the years.

Both did well at their crafts.

Rose strung together seven birdies, holing out from the bunker on No. 10 and ending his round with a 50-foot birdie putt that banged into the back of the cup. He played Pebble Beach and Monterey Peninsula for his practice rounds and realized he should have been at Spyglass "because it's a pretty tough course."

"There's some strong holes on it," Rose said. "And I heard some strange reports about Spyglass, like the first few holes are great, then it disappears into the hills and it's not that good. That's not what I saw. That's a pretty stellar golf course to me and really enjoyed playing it."

Timberlake played, too -- the guitar.

He didn't contribute any shots to their pro-am score, but Rose said the highlight was on the 16th tree when Timberlake grabbed a guitar for an impromptu performance, with Alfonso Ribeiro chipping in.

"That was a cool moment," Rose said. "Not many people saw it, because there was only like 20 people back there. That's obviously when you really appreciate how someone can grab a guitar, go a cappella and sound so awesome. You have a better appreciation. You see him hit not maybe so many great golf shots, but then you realize, 'Ah, that's pretty damn special right there.' So we all have our own skill set."

Reavie enjoyed the pure weather almost as much as he enjoyed watching putts go in. Golf has been a grind for Reavie since he missed nearly all of 2014 because of surgery on his left wrist and had to return to the Web.com Tour Finals last year just to get his PGA Tour card back.

"Even on days I putt well, I still don't make as many putts as I made today," Reavie said.

Some of the biggest stars had to settle for enjoying the weather.

Jordan Spieth, the No. 1 player in the world, chipped poorly by his standards and three times failed to get up-and-down for birdies on the par 5s at Spyglass Hill. He opened with a 71, along with PGA champion Jason Day. Dustin Johnson had a 70 at Spyglass, while Bubba Watson had a 73. Patrick Reed had a 72.

All of them are among the top 10 in the world and were at Spyglass with the celebrity rotation.

"A bit weak," Spieth said about his round. "I played the hardest holes on this golf course 4-under par, and then I played all the easy ones over par. Just kind of a bit odd. I just was not quite dialed in with the wedges or short game. But all in all, to actually shoot 1 under with what I felt like I should have shot today is promising, considering we're going to the two easier courses in my mind."

J.B. Holmes also shot a 66 at Spyglass Hill, while Phil Mickelson had a 68 while playing with a different setup in his driver that he regretted changing.

"Like an idiot, I switched drivers," Mickelson said.

He said his driver has weight ports that can be adjusted to affect the spin rate, and he didn't think he was getting as much as he wanted last week in Phoenix. So he made an adjustment and "hit some shots I didn't care for today."

"So I'll go back to my other driver," he said.