By the time Tiger Woods arrived on the grounds for his mid-afternoon tee time in the first round of the British Open, Royal Troon already had been rocked by roars celebrating a hole-in-one by South African Ernie Els and a double eagle from Englishman Gary Evans.

On a day of surprisingly gentle breezes from start to finish Thursday, Woods had seen many decent early scores and knew the normally wind-blown links likely would never play any easier.

He was unable to take full advantage of its vulnerability, but nevertheless couldn't complain about his 1-under 70, if only because it marked Woods's first sub-par opening round in a major championship since he won the 2002 U.S. Open at Bethpage. Attempting to end a run of eight straight majors without a victory, the world's No. 1-ranked player will go out Friday morning four shots behind co-leaders Thomas Levet of France and Paul Casey of England, both in at 5-under 66, a shot ahead of third-place Michael Campbell (67).

"It's a positive start," said Woods. "It's probably as easy as you'll ever see it . . . as good as it gets out there. But there some tough pins . . . and it was hard to get close on a lot of holes. You couldn't be too aggressive."

Casey and Levet were aggressive in the morning, especially when they saw the same benign conditions Woods encountered in the afternoon. Casey was particularly successful on the more difficult back nine, needing only 32 strokes with four birdies and a bogey, the lowest score of the day on that side.

"Every 12-year-old dreams of holing putts at the Open and teeing off with Phil Mickelson in the first round," Casey said afterward. "I think there were a lot of guys who dreamed of shooting 66 at the Open Championship. Luckily, I'm the one who's doing it."

Casey, who played college golf at Arizona State, drilled fellow alum and playing partner Mickelson (73) by seven shots in their threesome, and needed only 24 putts as he launched his third Open appearance with 10 one-putt greens and a chip-in for a birdie at the 438-yard No. 10. Casey, 26, missed the cut in his first two Open appearances, but earlier this season tied for sixth at the Masters, won by his friend Mickelson in April.

"There are a lot of young, talented players that are ready to win and have the game to win and he's certainly one of them," said Mickelson, who has never had a top-10 finish in this oldest major in golf. "The way he played shows how solid he is. I wouldn't be surprised one bit if he were to be on top on Sunday."

Levet got into the field here with an emotional victory in the Scottish Open at Loch Lomond last week. Though he hit only two fairways on the back, a 45-foot birdie putt at the 405-yard No. 7 helped immensely, and a 35-foot birdie putt at the 222-yard 17th allowed him to take a share of the lead two years after he tied for second in this event at Muirfield.

"Sometimes you learn from that," Levet said of his runner-up Open finish when he lost in a sudden-death playoff to Els. "I said, 'Look, this is the first time I was in a major in contention.' It's the first time I was about to win something, and there's nothing to be ashamed of.

"Life is going to go on and just try to enjoy the game and take some experience from that instead of crying in your locker."

There were no tears Thursday from Els, just a shrug over too many missed opportunities to go lower than his 69. Els was on the 17th tee at 4 under with a chance to tie for the lead, but walked off the green with a double bogey. His deep frown was in marked contrast to the beaming smile he'd worn two hours earlier, at the famous 123-yard Postage Stamp eighth hole.

The ball hit the putting surface about 10 feet in front of the hole, bounced once, then a second time behind the hole before spinning back and going into the cup. It was the seventh hole-in-one of Els's pro career, and the second in major championship play.

"That was beautiful, I tell you," Els said. "I was actually thinking 9-iron and Rikki [Roberts, his caddie] talked me into the wedge. I hit it really solid, and as I hit it I was saying to the ball 'get up, get up, get up.' It bounced nice and hard and had a lot of check on it. I just saw it on television and it actually went in from the back of the hole. From the tee it looked like it stopped and went in from the front. So it was definitely enough club."

Evans also chose the proper stick at the 560-yard fourth hole when he pulled a 5-iron out of the bag in the middle of the fourth fairway. He was 227 yards from the flag, but on links style courses, it's far better to hit short of the greens and allow the ball to release and run up. That's precisely what happened with Evans's second shot, the first so-called "albatross" of his life.

"The old boring sort of yardage and hitting to targets goes out the window," said Evans, best remembered for his final round at Muirfield two years ago, when he shot 65 despite a lost ball at the 17th that ended his championship hopes. "You just visualize the shot and give yourself a chance. There's a lot of imagination required for links golf."

Woods would like to imagine that his opening round ultimately will lead to his first stroke-play victory of the season. He has struggled with his driver, including the new Nike model he put into his bag at the Western Open two weeks ago, but won't have to hit it very often this week. He chose a 4-iron off many tees, the better to keep his ball in play on a day when he made four birdies and three bogeys.

He had several other opportunities to go lower, botching a three-footer that cost him a three-putt bogey from 25 feet at No. 7, then missed a five-footer for par at the 13th for his second straight bogey. He got himself under par for the round at the 542-yard 16th when he reached the green in two and two-putted from 30 feet, missing an eagle by one roll of the ball.

"You just play with what the golf course gives you," Woods said. "That's what the wind gives you, and that's what you have to do."

Ernie Els shot a 2-under 69 in a round that included a hole-in-one on No. 8.