ST. ANDREWS, Scotland >> After spending much of the past month maintaining that he is not dwelling on his brutal final-hole collapse at the U.S. Open, Dustin Johnson began this week’s British Open by shredding the venerable Old Course with a 7-under-par 65 on Thursday.

At the end of a first round that featured a typically Scottish menagerie of weather conditions, Johnson topped a leaderboard littered with major winners, including Jordan Spieth, who arrived here having already won the Masters and the U.S. Open this year.

Playing alongside Johnson, Spieth opened with a 67. Six players, including former U.S. Open champion Retief Goosen, former British Open champion Paul Lawrie and former Masters champion Zach Johnson, were between them after shooting 66.

Dustin Johnson said afterward that "there’s really no bad feelings" from the Open, adding that he believed he did "everything right" during the tournament at Chambers Bay.

In his mind, his three-putt from 12 feet on the 72nd hole, which allowed Spieth to win, was the result of inferior greens, not any flaw in his game.

"There was nothing you could do on those greens there to make the ball go where you wanted it to go," Johnson said. "I actually played really well and then it carried over to today."

That much, at least, was apparent right from the start as Johnson birdied two of his first three holes before eagling the par-5 fifth. He played his first nine in 5-under 31, and was one of many players to take advantage of placid morning conditions on the easier opening half of the Old Course. Ten of the top 12 players on the leaderboard at the end of the round had teed off before 10 a.m.

Spieth also shot 31 on the front. So did Lawrie, Johnson, Cameron Tringale, Rafael Cabrera-Bello and Robert Streb, who is in the group one shot behind Johnson. David Lingmerth, who teed off at 7:05 a.m., tied the course record on the front nine with a 29. Unfortunately for the Swede, he then returned to the clubhouse with a back-nine 40, leaving him with one of the more bizarre 3-under-par rounds of his career.

One player who did not seize upon the calmness of the early hours was Tiger Woods, who had vowed that he was on the verge of a breakthrough. But he looked remarkably similar to the shell of himself who competed at Chambers Bay. He shot an 80, followed by a 76, there.

Woods began Thursday with a poor opening tee shot, then plunked his second shot into the narrow creek in front of the green. He bogeyed that hole and the next, and finished with a 4-over 76, his worst score in four Opens at the Old Course.

Woods, now ranked No. 241, is tied for 141st in the 156-man field, putting him halfway to missing the cut in a second straight major. That would be a first for Woods in his career.

"I made so many mistakes," Woods said, adding that he was "angered a little bit" by his inability to make birdies.

Jason Day, who played in Woods’ group and shot 66, said he believed Woods’ mental response to adversity these days was tamer now than when he was dominant.

"He had that kind of killer instinct," Day said. "I think today he was just struggling a little bit, needed to put his mind somewhere else, and that’s kind of how he dealt with it."

Woods’s group, which also included Louis Oosthuizen (67), finished the round about 2:30 p.m., which was precisely when Phil Mickelson was beginning his. Mickelson, who has not won a tournament since the 2013 British Open at Muirfield, had an erratic opening nine (three birdies, two bogeys) but navigated the second nine with poise to finish at 2-under 70.

On the famous Road Hole, as the 17th is known, Mickelson — hardly a short hitter — opted to lay up with his second shot as the freshening wind was making the 495-yard par 4 play far longer. With the flag tucked perilously behind the deep bunker beside the green, Mickelson was not alone in approaching the 17th with caution and coming away with a bogey anyway.

The wet, windy and bitterly cold conditions in the afternoon made weather a perpetual topic for everyone on the course. Fans wrapped themselves in blankets while players covered up in foul-weather gear. Rickie Fowwler (72) wore big mittens in between shots, and Bernd Wiesberger wrapped a scarf around his head and neck in the style of a nun’s habit.

As difficult as the conditions were Thursday, the predictions for Friday were downright grim. Lots of rain and lots of wind whipping in from the North Sea is expected, combining to offer an overall feel that "could be Armageddon," according to the Englishman Danny Willett. Ernie Els said his group was told there was a "weather warning" for Friday, though he acknowledged, with a laugh, "I don’t know what that means in Scotland."

Tom Watson, the five-time champion of this event who is playing his final British Open this week, said he had an idea what it might mean. Watson has played in virtually every type of weather on these links courses, and he did not hesitate when asked about what he expected on Friday.

Referring to the leaderboards, which show under-par scores in red and over-par scores in black, Watson said: "You see all the red numbers today? You’ll see a lot of black numbers tomorrow, I promise you."

He added, "The golf course will take its toll."