OLD WESTBURY, N.Y. – Golf hasn't felt this easy to Dustin Johnson since he was making it hard for anyone to beat him.
Coming off a week in the Bahamas and switching back to his old putter to rely more on feel, Johnson ran off three birdies over his last six holes at Glen Oaks Club and finished with a 5-under 65 to trail Russell Henley by one shot after the opening round of The Northern Trust.
Johnson missed only two fairways and two greens Thursday afternoon, and he finished with a shot up the hill to 4 feet for one last birdie that gave him his lowest round since he won at Riviera in February to rise to No. 1 in the world.
''Today was much easier than it has been in the past,'' Johnson said. ''I've been saying it's close and I've seen signs of it. But today was the first day where I felt like all day I was really in control of the swing. Hit a lot of really good shots. Drove it well. Did everything really well. It's the first time in a long time I've done that.''
He specifically used as a reference the weeks leading into the Masters, when Johnson looked nearly unstoppable by winning three straight tournaments. And then he was stopped by a staircase in his rental home at the Masters, slipping in socks and wrenching his back. He had to withdraw from Augusta National the next day, and since then he has been trying to get over the back injury and get back his game.
The first of four FedEx Cup playoff events moved this year to Glen Oaks, a course no one in the field knows particularly well. It is spacious and immaculate, the contoured greens that can be difficult to negotiate outside of close range.
Henley brought a conservative strategy of aiming for the safe part of the green, and he converted eight birdies. Seven of them were from 12 feet or closer, a testament to how well he was playing. He also chipped in from 80 feet.
''I don't know what the key is, or the secret,'' Henley said. ''I just tried to hit the fairway, make sure I hit the green when I was in the fairway, and the greens are great and I rolled in a couple of putts.''
Scott Brown, Camilo Villegas and Chris Kirk were at 66, and it was an important start for Villegas and Kirk.
The top 100 in the FedEx Cup after this week advance to the second playoff event at the TPC Boston. Kirk is at No. 97, Villegas is one spot behind. It was even better for a few players who opened with a 67, such as Bubba Watson (No. 113), Martin Flores (No. 118) and Harold Varner III (No. 123).
Flores only got into the top 125 by finishing with an ace, a par and a birdie at the Wyndham Championship.
Phil Mickelson, meanwhile, needs to see a score much better than his 72, which featured two straight birdies at the end but also a pair of double bogeys. Mickelson has played in every Presidents Cup or Ryder Cup since 1994, and he is in danger of being left out of the Presidents Cup next month at Liberty National.
U.S. captain Steve Stricker has said he needs to see signs from the five-time major champion, and Mickelson knows that.
''I would love to be on that team, but I've got to bring something to the table,'' Mickelson said.
PGA champion Justin Thomas, still sluggish from a busy week of trying to deal with his new status as major champion, wasn't expecting much out of his game and dropped two shots early before he rallied for a 68. In his first start since his two-shot victory at Quail Hollow, Thomas was not introduced on the tee as the PGA champion.
''After the drive I hit, I'm kind of glad they didn't,'' he said.
He hit it on the toe of the driver, a duck-hook that he says would have gone about 130 yards. He was exaggerating. It went 221 yards after it clanged out of the trees and into the fairway, leaving him a 2-iron to the green when most players are hitting a wedge or short iron.
British Open champion Jordan Spieth had a 69, while Hideki Matsuyama, the No. 1 seed going into the PGA Tour's version of the postseason, didn't make a birdie and opened with a 74. Rory McIlroy made three bogeys on the back nine and shot 73.
Johnson switched to a TaylorMade Spider putter during the playoffs last year, and he stuck with that up until returning this week and going back to what he used when he won the U.S. Open last summer at Oakmont.
''I got a little bit more feel with the putter instead of the Spider I was using,'' he said. ''I was getting a little bit too mechanical and I was worrying about too many things when I was putting instead of just putting.''
He ran a long birdie putt some 15 feet by the hole at No. 2 and three-putted for bogey. After that, his speed was better and his game was sharp. The 65 was his best round since a 64 in the second round at Riviera.