Former champion Mike Weir of Bright's Grove, Ont., hits from the fourth tee in the first round of the Masters on Thursday. (Timothy A. Clary/Getty Images)

Chad Campbell stumbled on the final two holes, but retained the lead through one round of the Masters in Augusta, Ga., on Thursday.

Campbell shot a sizzling nine-under par through 16 holes, but bogeyed the 17th and 18th to open the tournament with a seven-under 65 at Augusta National.

He opened with five consecutive birdies, and later sank four birdie putts in a row before closing with the back-to-back bogeys.

"I got off on a roll and it is always nice to make a couple of birdies to start, much less five," Campbell said. "I felt like I was hitting it well all day.

"Unfortunately, I ended up with two bogeys to finish. But overall, I'm pretty happy with the round."

Campbell has a one-stroke lead on fellow Americans Jim Furyk and Hunter Mahan, the latter slipping to six-under with a bogey on No. 18.

Shingo Katayama and Larry Mize had five-under 67s.

"I hit a lot of really good iron shots and kept the ball in play with my driver," Furyk said.

Former Masters champion Mike Weir of Bright's Grove, Ont., is tied at four-under with Aaron Baddeley, Angel Cabrera, Tim Clark, Todd Hamilton, John Merrick, Sean O'Hair and Jim Perry.

"It is an extremely demanding tournament," said Clark, winner of Wednesday's par-three tournament.

"But I know what it takes to win this tournament and I certainly come here with that mind."

Plenty of players took advantage of the ideal conditions — sunny with a soft breeze and even softer greens — with 19 shooting in the 60s and 38 breaking par.

"By no means is it easy out there," Campbell said. "But if you hit good golf shots, you really get rewarded."

Weir had a birdie and a bogey on the front nine to make the turn at even par, then sank birdie putts on the 12th and 18th and earned an eagle on the par-five 13th.

"I played well, putted pretty well," he said. "But overall, was just steady, which is what I need to do around here.

"That is the lowest back nine I have ever shot here. It was definitely scoreable today."

Calgary's Stephen Ames finished at one-over, posting two bogeys on the front nine and two more on the back nine.

'I let a couple of shots slip away'

Tiger Woods began his round at 1:52 p.m. ET, in the second-last group of the round.

The four-time champion carded a two-under 70 for the fourth time, mindful that he won the tournament on the previous occasions.

"I'm pleased with the way I hit the golf ball, although I let a couple of shots slip away at the end," said Woods, who has never broken 70 in the first round of the Masters.

"Everyone was making birdies everywhere on the back nine, so I knew it could be had with good shots. I was in position to shoot four-under par and just didn't get it done."

Padraig Harrington, seeking to win a third consecutive major, opened with a three-under 69.

"We all know things will get a little tighter toward the end of the week," he said. "Today was definitely one of the more generous days ever around Augusta."

Phil Mickelson struggled in his opening round, shooting one-over.

Greg Norman, who shares the tournament record of nine-under with Nick Price, impressed with a round of 70.

Competing in his 52nd and final Masters, Gary Player was eight-over 78 and former champion Fuzzy Zoeller, also playing for the last time, fired a 79.

Arnold Palmer, 79, delivered the ceremonial first swing shortly after sunrise, whacking the ball down the right side of the fairway from the tee box.

With files from the Associated Press