The day's premier grouping included another player well versed in being No. 1, Tiger Woods, who played with Phil Mickelson at TPC Sawgrass for the first time since 2001 and for the first time overall since the 2014 PGA Championship.
The Players Championship is the only PGA Tour event Johnson has played more than three times and never finished in the top 10 (he's 0-for-9).
"I think DJ plays wonderful all the time", Bubba Watson said after playing with him.
"I felt like it was a really solid round", said Johnson, who started at the 10th and went out in five-under 31 before picking up his sixth birdie at the par-five second.
With its signature island green, the par-3, 17th hole is one of the most recognised in golf and will produce its fair share of excitement this weekend. "I was surprised to be able to play, first of all, so that was more of the surprise, just to be able to tee it up".
"I felt like the way I was feeling today, I should have shot something in the 60s", Woods told Golf Channel. "So if I want to keep it, I have to play well".
Johnson, 33, is in his 10th Players, where he has finished better than a tie for 28th only once, that being a tie for 12th past year.
Johnson, who has been world No 1 for 64 weeks, is under siege by those ranked No 2 to No 5 inclusive and he answered the challenge as the 33-year old only knows best.
Celtics embrace underdog role against Cavaliers
Even with their star power, the Warriors play team basketball and move the ball better than any team in the league. It's just a sports town. "So why not the guy that's been in the finals the last X amount of years", DeRozan said.
The final design of SpaceX's Falcon 9 rocket launches today
The "block 5" version of the craft features a number of design changes the company claims will improve performance and safety. Nowadays, NASA sends astronauts to the International Space Station using Russia's Roscosmos space program.
Southampton win at Swansea to relegate West Brom
Hughes called it 'one of the poorest hotels we've stayed in.' Now the club itself has made this review official. We don't know what will happen tomorrow and at the weekend we must try and do our part and try to win.
"I definitely want to stay there but if someone passes me it's not going to change anything", he insisted, in a blow to those seeking stories beyond birdies and bogeys. I'm sure he was nervous playing that hole. "If I don't, someone's going to pass me, which is OK". In his previous nine starts, his best finish was a tie for 12th past year. "But now it's more like ... if I remained No. 2 and won majors, and was No. 1 for a long time and won six, I'd take the first one".
"Today was a pretty good day for scoring", Johnson said. "And if I can show myself that I can compete out here and play well out here, then I'm going to Byron Nelson".
"Obviously, you see some guys shooting 6-under par or so and know it was out there, " McIlroy said. "I just kind of ran out at the end". And then the world's No. 1 player picked it up quickly, and they were on their way.
"You've got four par-5s - given the right wind, even I can get to all four of them".
Johnson played like he was determined to keep the No. 1 ranking, which he could lose if he finishes 12th or worse.
'It was a big deal to get there and it's a big deal to stay there. "I want to play good golf". U.S. Open champion Brooks Koepka is another shot back, and Northern Ireland's Rory McIlroy is at 1 under along with Zach Johnson. "I mean, I unloaded everything [in the swing]".
"That was about as unlucky a round as I've probably ever had", Spieth said.
Koepka, who said he had his hand in ice all Wednesday night, was asked why he didn't withdraw. If I don't feel like I can win I won't tee it up.