ST. ANDREWS, Scotland -- The last test for Louis Oosthuizen was his second shot to the 17th green at St. Andrews, where the pin was planted perilously behind the Road Hole bunker.
He safely sent his 5-iron through the green and onto the 18th tee, where it stopped about six feet away from where Paul Casey was about to hit. Lee Westwood walked over to the ball and acted as though he was going to smash it back at Oosthuizen.
Even that might not have stopped him Saturday in the British Open.
Oosthuizen opened with a nervous bogey, then settled down quickly on another windswept afternoon for a 3-under 69 that gave him a four-shot lead over Casey and a chance to become the first player in 46 years to win his first major at the home of golf.
Ernie Els called him Saturday morning to wish him and well. Gary Player left him a message at his hotel. Maybe it's time for the 27-year-old Oosthuizen to start thinking he could be the next South African with a claret jug.
''I don't think anyone was thinking I was going to be up there,'' Oosthuizen said. ''You've heard yourself, no one can actually say my surname, so they don't even know who I am out there. It's great being up there. I just want to enjoy everything about it. I loved it out there. It was great fun for me. And hopefully, tomorrow will be the same.''
Oosthuizen (WUHST-hy-zen) was at 15-under 201. A victory today would make him the first player since Tony Lema in 1964 to win his first major at St. Andrews.
''The Open at St. Andrews would be something special,'' Oosthuizen said. ''It's one of those things you dream of.''
Casey went out in 31 when the wind was at its strongest, and mostly into his face. He finished off a bogey-free round of 67 that puts him in the final group of a major for the first time. He was at 11-under 205.
It might be a two-man race between players who have never seriously challenged in a major.
Oosthuizen was seven shots clear of Martin Kaymer of Germany, who had a 68 and was alone in third. Another shot behind -- and eight shots out of the lead -- were Henrik Stenson (67), Alejandro Canizares (71) and Westwood (71), who didn't make a birdie on the front nine but did well to at least stay in the game.
Americans have won six of the last eight Opens at St. Andrews, but they have disappeared in this one. Dustin Johnson birdied his last two holes for a 69 and was nine shots behind.
Tiger Woods, who won the last two times at St. Andrews by a combined 13 shots, has never been within four shots of the lead all week, and he wasn't even close Saturday. He had four long eagle putts -- only one of them on a par 5 -- and three-putted for par on three of them to shoot 73. He was 12 shots behind, sure to match his longest start to the season without a victory in his seventh tournament.
''I'm playing better than my position,'' said Woods, who was tied for 18th. ''I certainly have had a lot more putts on the greens that I ever have, and that's something that has basically kept me out of being in the final few groups.''
Phil Mickelson, who had a chance at the start of the week to go to No. 1 in the world, was another shot behind. Whatever momentum he had was lost with a 5-iron that he hooked out-of-bounds for a double bogey on No. 16 for a 70.
The South African heritage at golf's oldest championship dates to Bobby Locke winning four times in a nine-year stretch after World War II. Player won the claret jug three times, and Els was the most recent in 2002.