Karlsson made the most of an early tee time to shoot a 2-under 68 and share the lead with Jeev Milkha Singh in Thursday's weather-delayed opening round at long and treacherous Oakland Hills.
Karlsson double-bogeyed the very first hole, certainly no way to start a major championship. So caddie Gareth Lord pointed out the obvious.
"My caddie said, 'We played with Tiger in the U.S. Open and I think he took a 6 on the first hole pretty much every day. You can shoot a good round out here as well,' " Karlsson recalled.
With that motivation, Karlsson birdied the next three holes on the way to one of only six subpar scores in the opening round.
Andres Romero of Argentina was 2 under through 16 holes when play was suspended for the day because of darkness. He bogeyed the final hole to finish a 69.
He was among 18 players still on the course who completed their rounds at the same time second-round play was already beginning elsewhere on the course. The first round had been suspended for almost an hour-and-a-half by inclement weather late in the afternoon.
Singh, the first native of India to get a European Tour card, also showed some resilience after bogeying the first hole.
He did not credit Tiger for his turnaround, however.
"The most important thing to learn [about] a major championship is to stay patient," said Singh, playing in just his second PGA and only his ninth major. "If you hit a bad shot, you've got to take your medicine."
Singh took his medicine -- and came back with an eagle on the second hole.
Phil Mickelson, who also recovered from bogeys on his first two holes, got into red numbers before bogeying the last hole for a 70. He was joined there by Anthony Kim, Ryan Moore, Rod Pampling, Charlie Wi, Brian Gay, late addition Michael Allen and Angel Cabrera.
Woods, of course, had knee surgery soon after his stirring playoff victory over Rocco Mediate at the U.S. Open and is sidelined until next year. His absence has turned the year's last major into a free-for-all. That was evidenced by the number of players who had at least a share of the lead in the opening round.
Karlsson got to 4 under through 13 holes and had a two-stroke edge at one time. Among the others who at least got a piece of the lead were Singh, Romero, Mayfair, O'Hair, Kim, Wi, Gay, Cabrera, Jim Furyk, Retief Goosen, Ben Curtis, Padraig Harrington and Jonathan Byrd.
Whew! That sure is different from most majors when Tiger is on the prowl.
Oakland Hills -- dubbed "The Monster" by Ben Hogan -- proved to be a stout test for everybody. When the wind picked up in the afternoon, Karlsson knew things were only going to get tougher.
"There's not going to be many scores under par. Definitely not in the afternoon," he said.
Romero was the only member of the 156-player field to go below par with a later tee time. He had to have a rules official help him find his marker in the rough at the par-3 17th on Friday morning, then he chipped on and made a short putt for par. After a fine tee shot on the par-4 18th, he came up short of the green with his second shot, chipped to 10 feet and ran his par putt 3 feet by.
"I'm very happy with the way I played," he said. "It was a very good round and a very good start."
The finishing holes at Oakland Hills are considered among the most difficult in golf. But they weren't the only hard holes on Thursday. Several of the top players were scratching their heads after watching a good round ruined by a late collapse.
Kim got to 2 under but closed with two bogeys in his 70. Furyk bogeyed his final three holes to finish at 1 over. Goosen went out in 33 but came home in 39. Curtis was 3 under without a bogey through 10 holes and then played the final eight 6 over. Byrd was on top at 3 under after eight holes and then bogeyed three of the next four.
And Harrington, the two-time defending British Open champion, birdied the first three holes then went cold. He had five bogeys the rest of the way in a 71.
"It's all about staying patient for the first three days and I need to get my head around that," Harrington said.
Kenny Perry, chasing his fourth win of the year at the age of 47, had to withdraw after shooting a 79 because of vision problems stemming from a scratched cornea.
At least he won't have to battle Oakland Hills again. Ernie Els said it deserved the "Monster" moniker.
"Conditions were really tough," said Els, who shot a 71 but talked as if he had a 101. "The breeze was blowing, the fairways were firm and it was really tough to keep the ball in play on the fairways. And obviously the greens were really firm as well, and there were some really tough pin placements too.
"It was a real beast."