Masters sophmore Snedeker (2nd from left) had a chance to join leaders Rose and Immelman, but bogeyed 18 to finish one back. Tiger is four off.
AUGUSTA, Ga. (AP) -- Justin Rose has the first round of the Masters down pat.
It's the rest of the tournament he must master.
Rose shot a 4-under 68 that put him atop the leaderboard on a warm, sunny opening day that featured Ian Poulter's hole-in-one, a solid start to Zach Johnson's title defense and Tiger Woods poised for a run at another green jacket. Sound familiar? It should.
In 2004, the Englishman led after the first and second rounds but faded to a tie for 22nd. Returning to Augusta National a year ago, Rose surged to the front again with a 69 on Thursday, but didn't come close to matching that score the rest of the weekend, settling for a fifth-place tie three strokes behind Johnson.
On Thursday, he got off to another quick start and was tied for the lead with South African Trevor Immelman.
"I've learned you can't count your chickens too early," said Rose, who won the Order of Merit as the top golfer on the European Tour in 2007. "Obviously, the first round has been great to me here."
Woods prefers to do his best work on the weekend. In his four previous Augusta wins, he twice trailed by three shots after the first round, another time by five, and was a daunting seven shots back in 2005.
Woods, who shot a 72, remained the overwhelming favorite to win his fifth green jacket -- the starting point for an unprecedented Grand Slam.
"I feel good about how I played all day," he said. "I hit a lot of good putts that just didn't go in. I've just got to stay patient out there and hopefully it will turn."
After putting up nothing but pars through the first 12 holes, Woods was on the ropes a bit with two straight bogeys. But the world's No. 1 player quickly pulled himself up by chipping in for eagle from just off the green at No. 15, bringing out his first fist pump of the tournament. He parred out from there.
Rose actually struggled in the beginning, with bogeys on two of the first four holes. But he played the rest of the round at 6 under, surging past early clubhouse leaders Poulter and Robert Karlsson, who posted 70s.
"Eventually you've got to say, 'OK, it's time to step up,'" the 27-year-old Rose said. "But I'm not putting too much pressure on myself. I'm just coming into my prime, I feel. I've got 10 to 15 good years in front of me."
Immelman played a bogey-free round that seemed to come out of nowhere. He missed the cut in four of his eight events this year, and has yet to finish higher than 40th in a stroke-play tournament.
"Obviously, my form has not been too stellar so far this season," Immelman said. "I had to just stay patient with myself and know it's in there somewhere. You just have to remember you're a fairly good player."
Johnson, a low-key guy from Cedar Rapids, Iowa, came into the week as little more than an afterthought to Woods, despite an improbable win last year.
Johnson's victory was viewed as a fluke of the weather. Cold, blustery conditions made it possible for him to play it safe and claim the green jacket with a 1-over 289, tied for highest winning scorer in Masters history.
Still, he's the only player in the field with a chance to win back-to-back titles, a feat accomplished by only three other golfers. His defense started with a 70.
"All in all, a pretty good solid round," said Johnson, who shot 35 on the front side and matched it on the back. "I'm very, very honored to be the defending champion."
Poulter, known as much for his garish outfits and eccentric hairstyles as his shotmaking, sent the patrons into a frenzy with his hole-in-one at No. 16, a 170-yard gem known as Redbud.
With more fans than ever able to watch from the adjacent hill, Poulter launched an 8-iron over the water that landed about 20 feet right of the hole, curled up and around the ridge -- and rolled right in. The patrons roared as though it was the back nine Sunday.
"There was an unbelievable buzz," said Poulter, who actually went a little tame with his attire: lime green pants with matching visor, and a striped white shirt. "That was a special moment. The hairs on the back of my neck were standing up. It was great."
Poulter has never had any trouble stirring things up -- whether it's his fashion sense or willingness to say whatever's on his mind. He's already proclaimed himself capable of moving up to become the world's No. 2 player behind Woods -- quite bold, considering he's never won in the U.S. and has only one Top 10 finish in a major.
"Basically, I was saying how good Tiger was," Poulter said, "and how achievable I think it is to get to the No. 2 spot. If you play well over a year's period or a two-year period, you can get there."
Master rookie Brian Bateman and Brandt Snedeker were one stroke off the lead at 69, with Lee Westwood and Jim Furyk also at 3 under and trying to complete their rounds as darkness settled over Bobby Jones' course. Stephen Ames also was part of the group at 70.
Two-time Masters winner Phil Mickelson is seen as Woods' most likely challenger. He birdied the first two holes to jump right on the leaderboard, though a short miss at No. 6 slowed his momentum. Lefty remained at 1 with four holes to play.
Woods and everyone else teed off about an hour behind schedule after soupy fog blanketed the course just past sunrise. He got off to a shaky start, pulling his drive up against the second cut to the left, then missing the green to the right with a towering second shot.
He chipped 8 feet past the cup, but managed to sink the putt to save par, the ball curling around the lip before dropping in. That set the tone for a solid if unspectacular round.
Woods drove his second shot at the par-5 13th over the green, needed two more pitches to keep it there and took bogey. He made his second straight bogey at No. 14 after driving into the trees, but finally put a red number on the board at the next hole with his chip-in from about 25 feet.