Dustin Johnson is one of the biggest hitters in golf, and he grabbed a little attention from the Big Three at the Memorial on Thursday at Muirfield Village in Dublin, Ohio.

But not all of them.

Johnson had three bursts of birdies and shot an 8-under-par 64 for a one-shot lead over Brendan Steele.

Two shots behind was Jason­ Day, the No. 1 player in the world and a member at Muirfield. Day rallied with three birdies and an eagle on the back nine for a 66. That’s his best score on this course that Jack Nicklaus built.

The other part of the Big Three lagged behind.

Jordan Spieth’s putter saved him in a scrappy round that he turned into a 70. Spieth­ one-putted his opening seven holes. Rory McIlroy went back to a conventional putting grip and shot a 71.

McIlroy, who won two weeks ago at the Irish Open, played with Spieth and never got any momentum.

McIlroy took double bogey from the bunker on the par-3 16th and turned a birdie chance into bogey on the par-5 seventh on his way to a 71.

The biggest change for McIlroy was going back to a conventional putting grip, after changing to a cross-handed grip during the Florida swing ahead of the Masters. McIlroy said he took 127 putts in his Irish Open victory and felt his pace on putts was not where it needed to be, especially for the faster greens of Muirfield Village and Oakmont in two weeks for the US Open.

‘‘I felt like to give myself the best chance of having a little bit more feel and a little bit more visualization and stuff, I just needed go back to what I’ve done for most of my career,’’ McIlroy said.

Johnson’s round was similar to Spieth’s in terms of putting. The difference is he had more putts for birdie. Four of his 10 birdies were from at least 10 feet, including a 30-foot birdie putt on the 13th hole.

He hasn’t won since Doral in 2015, though he has had 14 top-10 finishes since and only one missed cut.

‘‘With me, it has everything to do with the putter,’’ Johnson said. ‘‘I rolled it well today. I’ve been working pretty hard on the putter, and I felt like it’s finally starting to pay off.’’

Hudson Swafford tied the Muirfield Village record with six birdies on the front nine for a 29. His momentum stalled with a bogey on the par-5 11th, and he shot 66. Kevin Streelman and Jason Bohn were another shot behind.

Spieth hit only two fairways and three greens on the back nine, but he didn’t pay for it. He holed a 12-foot par putt to start his round on No. 10, and his short game was superb as ever. Dating to his victory at Colonial on Sunday, he had 16 consecutive one-putt greens. The streak ended when he missed a 12-foot birdie putt on the 17th.

‘‘Just didn’t get off to a good start on the first few holes striking, and from there it got me thinking about stuff,’’ he said. ‘‘But my putter made up for it for the most part. To shoot 1 under on my front nine was by far the best that I could have possibly shot.’’

European — Six players shared the lead after the opening day of the Nordea Masters outside Stockholm

Andrew Johnston, Clement­ Berardo, Florian Fritsch, Marc Warren, Scott Henry, and Sebastien Gros all shot 5-under 67 on the Bro Hof Slott course.

Lee Westwood, a three-time winner of the tournament, was one shot behind after six birdies and two bogeys in his opening round.

World No. 6 Henrik Stenson was five strokes behind the leaders, finishing the day on par.