Not that he’s dwelling on what happened eight years ago.

“I’m 40 years old,” the Dane said on Thursday, “and there might just be a little bit more in me.”

Bjorn ripped off three straight birdies coming down the last holes. Even with a stumble at the final hole, he was in the clubhouse with a one-stroke lead over Miguel Angel Jimenez and six strokes ahead of US Open champion Rory McIlroy, who got off to a sluggish start.

While McIlroy was the clear favorite, Bjorn didn’t even get into the tournament until Monday as an alternate, giving him a chance to make up for his collapse at the ‘03 Open.

That’s when he squandered a two-stroke lead over the final three holes, largely by needing three swings to escape a bunker on the par-3 16th. Ben Curtis went on to claim the claret jug in one of golf’s greatest shockers.

“I probably didn’t dwell on it as much as some people thought,” Bjorn said. “I think the only really hard time I had with it was when I came back to Troon the year after. I felt that was difficult because it just became so fresh in the mind: The Open championship.”

Bjorn got some good fortune at the 16th this time. He thought his 9-iron was headed for the bunker, but the ball took a fortunate bounce and rolled down toward the cup. He made the putt for his third birdie in a row.

“We all know what it’s like,” Bjorn said. “A bounce here or there, and then it goes either wrong or right. Today, it went my way.”

There was no sign of Curtis, the one who beat him last time. The American champion will have trouble just making the cut after shooting a 77.

McIlroy had not played since his dominating win at Congressional last month. The Northern Irishman looked a bit rusty and put himself in an early hole by making bogeys on two of his first three holes.

McIlroy had trouble hitting it straight off the tee and looked shaky with the putter, hardly resembling the player who blew away the field by eight strokes for his first major title, setting a US Open scoring record at 16 under.

Of course, there’s still plenty of time for a comeback. All eyes will surely remain on McIlroy, who has emerged as the new face of golf while Tiger Woods sits out his second straight major, trying to heal an injured leg.

“It was a day where you just needed to grind out a score,” McIlroy said. “Anywhere around even par was a good start.”

Playing right behind McIlroy was England’s Luke Donald, ranked No. 1 in the world and coming off a four-stroke win in the Scottish Open. His day went much like McIlroy’s, leaving them both to settle for 71s.

Dustin Johnson, one of the top American hopes, got off to a dismal start but turned things around with an amazing finish. He had two straight birdies, then made a hole-in-one at the 16th, the ball hooking onto the green, catching the flagstick — and disappearing from view.

Back on the tee, Johnson high-fived playing partner Ian Poulter, celebrating the first ace at the Open since Thomas Levet’s in the final round at Turnberry two years ago. Johnson made another birdie at 17 before a closing bogey left him with a 70.

The top American was a big surprise. Kyle Stanley qualified for the tournament on Sunday with a runner-up finish in the John Deere Classic, then hustled across the Atlantic on a chartered jet to compete in his first major as a pro.

He hardly looked like a rookie, shooting a 68 that left him tied with England’s Simon Dyson, an alternate like Bjorn. Even after a bogey at the tough 18th, Stanley chest-bumped his caddie, a big smile on his face.

The Americans are eager for Johnson or Stanley — anyone — to break through. The US has gone five straight majors without a title, its longest drought in the modern Grand Slam era.

Bjorn played well early in the year, winning the Qatar Masters against a strong field and beating Tiger Woods in the World Match Play Championship. But the Dane missed the cuts in four of five events before the Open, needing help just to make it to the first tee.

He was one of the last players into the field, getting his spot late Monday when Vijay Singh withdrew.

“I’ve been very uncomfortable on the golf course for a long time,” Bjorn said. “If I can last all the way until Sunday, well, only time will tell. But I’m very, very delighted with today.”

Bjorn did tear up when someone asked about his father, who died a couple of months ago after a long illness. The loss had a profound effect on the son, undoubtedly contributing to his recent slide.

“He meant a lot to me,” Bjorn said. “He would have been very proud of what I did.”

The 47-year-old Jimenez was right in the mix. The portly Spaniard capped off a bogey-free round with a brilliant chip at the 18th, saving par with a short putt after he drove into the tall grass.

Then, lighting up his familiar cigar, Jimenez headed off to the putting green.

Also making a late-afternoon charge was England’s Tom Lewis, who shot a 3-under 32 on the front side. Maybe he was destined for success — his father named him after five-time Open champion Tom Watson. Sweden’s Fredrick Andersson Hed also made the turn with a 32.

Poulter and 51-year-old Mark Calcavecchia were among those at 69. Sergio Garcia was another stroke back.

Defending champion Louis Oosthuizen and Phil Mickelson, the last American to win a major, played in the afternoon.

The weather is always the biggest unknown at the British Open. Punishing gusts whipped across Royal St. George’s during the practice rounds, and storms can blow in off the sea at any time.

For the most part, the nasty weather held off on Thursday.

The wind wasn’t nearly as daunting on Day One, especially for those who went out in the afternoon in relatively benign conditions. There was an occasional heavy shower in the morning, but the course dried out as the day went on.