Cameron Smith is among the early frontrunners at the US PGA Tour's Sony Open in Hawaii while Jordan Spieth's charge was derailed by a tree-studded quadruple bogey.
Johnson, the 2009 victor at Waialae in Honolulu, had seven birdies in his seven-under 63, joining early pace-setter Chris Kirk atop the leaderboard in the US PGA Tour's first full-field event of 2018.
Twice Major victor Johnson carded a bogey-free seven-under 63 that included a birdie at the 18th to grab a share of the lead with Kirk, who had four birdies over the final six holes.
Johnson got off to a hot start in his pursuit of Kirk, with birdies at the first three holes. Harman, meanwhile, continues his stellar play of late after a third-place finish at last week's Tournament of Champions.More news: United Nations says Trump slur on 's…hole' countries is 'racist'
Kirk, whose most recent victory was at Colonial in 2015, said a return to his old putting routines had paid off on the greens. Stanley capped his round with an eagle at the par-five ninth, rolling in a 41-footer.
Another Aussie, Steve Allan, was also at 2 under with a round that included an eagle, four birdies, ten pars, two bogeys and a double bogey.
Spieth's tee shot went left as the first of four consecutive shots that would hit trees as he made an eight, finishing the day in a tie for 65th.
Peter Malnati, Daisuke Kataoka, Matt Every and Tom Hoge opened with 5-under 65s.More news: Societe Generale Lowers Bank of America (BAC) to Hold
His next shot also hit a tree and was barely advanced, getting him just 18 yards closer to the hole and still in trouble.
He rallied somewhat with a birdie at his final hole for a one-under par 69.
Joining him will be good friend and defending champion Justin Thomas, who secured back-to-back 67s to be 6 under for the tournament.
Thomas could not reach the heights of his sensational 59 on day one 12 months ago, but he kept a birdie off his card and was clearly at ease having Phil Mickelson's former long-time caddie Jim "Bones" Mackay on his bag with his regular caddie recovering from a foot problem.More news: Habit driving crude oil prices higher early Wednesday