Scott started with six straight pars before birdies at the seventh and eighth holes made him the first player to reach 11 on a glorious day at Royal Lytham & St. Annes. The Aussie started one stroke behind Snedeker, who went through the first two rounds without making any bogeys.
That all changed on the far end of the course, where Snedeker had four bogeys in five holes. His score dipped to 7 under, leaving him tied for second with Tiger Woods.
Woods got off to a sluggish start with a couple of bogeys, but he made the turn at 1-under 33 after closing the front side with three birdies in four holes. He hasn't won a major title in more than four years, the last of his 14 championships coming at the 2008 U.S. Open, before his personal life imploded and his body was wracked by injuries.
Snedeker got off to a solid start, but the trouble started when he came up short of the green at the fifth and couldn't get up and down, taking his first bogey of the Open after 40 holes without one. Just like that, they started coming in droves.
At the sixth, the quick-playing Tennessean knocked his ball into one of the 206 bunkers on the course, the first time all week he'd been in the sand, and he was forced to hit sideways just to get it out. A birdie at the par-5 seventh provided a brief glimmer of hope, but Snedeker bogeyed the next two holes and made the turn with a 3-over 37 for the round.
Scott was steady as can be, making pars on the first six holes before two straight birdies suddenly gave him some breathing room on the rest of the field. With his long putter, he rolled in a 25-footer to become the first golfer in the tournament to reach 11 under. His turned with a 32, holding a four-stroke lead on Snedeker and Woods.
Woods' very first shot rolled off the back of the green at the par-3 opening hole. His chip was a little too delicate, stopping 8 feet short of the hole, and he missed the putt. Another bogey at the third rekindled memories of his performance at Olympic last month, where he was tied for the U.S. Open lead after 36 holes but faded badly on the weekend.
This time, he got back in the game.
Woods sparked his round with a 60-foot birdie putt at the sixth, earning his first fist pump of the day. He nearly closed the front side with four straight birdies — his putt from the fringe of the eighth green stopped about an inch shy of the cup. He shook that off by knocking his tee shot at the par-3 ninth to 4 feet, rolling in the putt for a halfway score of 33.
Also showing remarkable poise: 22-year-old Thorbjorn Olesen of Denmark, who was just thrilled to be playing in the penultimate group with his childhood hero, Woods. The youngster made a stunning up-and-down from a bunker for a birdie on No. 7, rolled in another birdie at the eighth, and made the turn still holding at 5 under.
Zach Johnson had the best round among those in the clubhouse, signing for a 4-under 66 that left him at 5-under 205 overall. If the wind picks up Sunday, he might have a chance to make a move on the leaders.
Three-time major winner Ernie Els also was at 5 under.
The weather along the Irish Sea was spectacular, sunny and warm, with maybe just enough wind to fly a kite on the beach. The big gusts are expected to arrive for the final round, though the forecast can't really be trusted in these parts.
Taking advantage of the favorable conditions, Masters champion Bubba Watson made a charge up the leaderboard before the last group teed off. He played the first 13 holes at 5 under, starting the back side with three birdies over a four-hole span. But a bogey at the 14th and a double-bogey at the 15th left him with a rather disappointing 2-under 68.
He settled for a 208, knowing those two poor holes likely ruined his chances of making a serious challenge for his second major title of the year.
Playing the geriatric contender role that Tom Watson nearly pulled off for a win at Turnberry, 52-year-old Mark Calcavecchia surged into contention with a 31 on the front side and a 4-under score overall. But he couldn't keep it going, either, finishing with a 69 and even with Watson at 208.
India's Anirban Lahiri gave the gallery a thrill when he aced the 150-yard ninth hole with a 9-iron.
Even before the hole-in-one, it already had been a memorable British Open for Lahiri's homeland, which had two players makes the cut in golf's oldest major for the first time. Jeev Milkha Singh also got through to the weekend.