Dustin Johnson plays like his former World No. 1 self at FedEx St. Jude Classic, leads by one after second-round 63

It's been just under a month since Justin Thomas overtook Dustin Johnson for World No. 1, but Johnson's play on Friday at the FedEx St. Jude Classic would indicate that's been too long of a layoff from the top spot for the now World No. 2. Teeing off in the morning wave, Johnson picked apart the difficult TPC Southwind, firing a seven-under par 63 and making it look easy at a place he's done so before, winning the event in 2012.

"It's never easy, but I feel like I'm playing pretty well," said Johnson, who leads by one at 10-under 130 through 36 holes. "I'm swinging the club very well, I know that if I can drive it in the fairway that I'm going to get myself a good look for birdie. I felt like I did that well pretty much all day today. Hit a lot of great shots in there and had a lot of really great looks at birdies."

Beginning his round on the back nine, Johnson picked up a birdie on his opening hole, the par-4 10th, but bogeys at the tricky 12th and 13th holes dropped him to one over on the round. That was quickly forgotten when he rolled in a 20-footer for birdie at the par-3 14th and then got up and down for birdie from a greenside bunker at the par-5 16th. He salvaged a one-under 34 on his front, and then took charge on the back nine, starting at the par-4 first, where Johnson one-hopped his 110-yard approach shot for eagle.

He'd go on to make four more birdies en route to a back-nine 29 highlighted by his impressive play with the driver. He ranks first in the field in strokes-gained/off-the-tee this week.

"When I'm playing well my ball moves left to right all the time," he said. "Right now it is and I feel like I'm swinging good and have a lot of confidence in my swing, and here, especially where you've got to start it, because you got to hit the fairways out here, you got to trust it and I feel like I'm doing that very well right now."

If Johnson's able to keep it rolling and win this weekend, he'll take back his spot at the top of the Official World Golf Ranking, a good place to be heading into the U.S. Open at Shinnecock Hills.

Ryan Blaum and Andrew Putnam, who each shot six-under 64s, trail Johnson by one at nine-under 131. C.T. Pan and Wesley Bryan are at eight-under 132.

Three back at seven-under 133 Brandt Snedeker, who carded a bogey-free eight-under 62, the low round of the week and his lowest round on the PGA Tour since he posted a first-round 63 at the 2016 Sony Open in Hawaii. The eight-time tour winner is in search of his first top 10 since last year's U.S. Open at Erin Hills, where he tied for ninth before making just one more start and seeing his season get cut short due to a sternum injury.

Brooks Koepka is tied for ninth at five-under 135 after shooting a one-under 69.