American Harold Varner III birdied the 18th to take a share of the first-round lead with England's Justin Rose as the PGA Tour returned on Thursday in Texas.
Both players hit bogey-free seven-under-par 63s at a quiet Colonial Country Club, with no fans present.
Northern Ireland's world number one Rory McIlroy shot a two-under-par 68.
The early starters observed a poignant minute's silence at 8.46am local time in memory of George Floyd, the African American who died in police custody.
Eight minutes and 46 seconds is the length of time Floyd was filmed being pinned under a white officer's knee. His funeral took place in Houston, Texas on Tuesday.
Varner III, one of the few black American professional players on the circuit, spoke at length with PGA Tour commissioner Jay Monahan before this week's Charles Schwab Challenge. They discussed the Tour's "potential role in the national conversation and solution" amid global protests in support of the Black Lives Matter movement against racial injustice.
On the course, Varner III birdied his first two holes and was four under after nine. He then birdied the 10th and 12th holes but missed opportunities to join Rose at the top of the leaderboard before holing from 10 feet on the last.
When asked whether the death of Floyd, and global protests had affected his play, he told Sky Sports: "I didn't think about it out there. I got in my zone. I love playing golf and am fortunate to do this for a living,.
"The platform I have is through golf so I know playing well is a part of that. It goes to show how life is precious and you take every day for what it is."
Normally, Varner III's final birdie would have been met with a deafening roar. But these are not normal times.
The eerie silence that followed was a stark reminder of how lacking in atmosphere the day felt.
South Korea's Sung Kang hit an ace at the par-three-13th but there was no fist-bumping with his playing partners or caddie, just a walk to the green to pluck his ball from the cup.
Gone too were the huge spectator stands that frame many greens. That allowed television viewers to see more of the course, but they were also treated to some colourful language that may otherwise have been drowned out by spectator noise.
And while social distancing guidelines were in the main reasonably well followed, there were lapses, such as when Varner III signed a ball after finishing his round and handed it to a woman who gingerly accepted it with her fingertips, or the fist bump he exchanged with a man on his way to the scorer's hut.
Varner III was by no means the sole culprit, but his actions were magnified by cameras following his every move as he left the 18th green.
But, as McIlroy pointed out before the tournament, mistakes will be made as they adjust to a new way of playing.
This is the first PGA Tour event since The Players Championship was abandoned after one round on 12 March because of the coronavirus pandemic.
The first five tournaments are being played behind closed doors but the Tour hopes to have fans at the Memorial event in Ohio in July.
Rose, who set the early pace, started on the 10th hole and chipped in from the edge of the green with a fairway wood to open with a birdie.
He was four under after seven and told Sky Sports: "I didn't play particularly well the first six or seven holes but the putter was hot."
Rose, who won this tournament in 2018 with four rounds of 66 or better, then had a run of three birdies from the first before finishing with six straight pars.
Marquee group fails to fire as friends' fortunes fluctuate
The top three in the world, McIlroy, Jon Rahm and Brooks Koepka were all drawn to play together. All three birdied the first but were unable to build on that early momentum.
McIlroy was back at level par after bogeying the sixth but was two under by the turn. However, nine straight pars followed.
American Koepka, ranked third in the world, had four birdies and two bogeys in his two-under 68, while Spaniard Rahm, bogeyed the last to finish on one under par.
The group ahead of them featured American friends Justin Thomas, Jordan Spieth and Rickie Fowler, who shared an 'air high-five' as they finished up on the 18th.
World number four Thomas had the bragging rights with a six-under 64, to sit one off the lead with Jhonattan Vegas, Abraham Ancer and Collin Morikawa.
Spieth, who has fallen to 56th in the world rankings, is one of nine players a shot further back on five under, but Fowler had four bogeys in his final five holes to fade to three over.
Elsewhere, Ian Poulter posted a solid four-under-par 66, while fellow Englishman Matt Fitzpatrick joined McIlroy on two under.
Northern Ireland's Graeme McDowell is one under, with England's Matt Wallace a shot back after carding a 70, while compatriot Danny Willett took 71 shots.