Holding the overnight lead with Justin Rose, Varner hit a wild opening drive at the tenth on his way to a triple-bogey seven and was still over-par for his round until holing a 30-footer at the fourth.
The PGA Tour went three months without playing.
Rory McIlroy's seven-under-par 63 in the second round at Colonial on Friday suggests he has adjusted to golf without the galleries, though the world No. 1 says the silence that meets his birdie putts took some getting used to. Fans gathered on the balcony of an apartment complex along the 14th, which also brought out the first, "Get in the hole!" since the PGA Tour returned for the first time since March 12 because of the coronavirus pandemic. "It just does feel like I'm playing at home with some of my buddies".
But, maybe excessively positive, Spieth ran his birdie putt 3 feet past the hole. But once you get into it, it's the same. "You know, I like to feed off the crowds".
Former world number one and three-time major champion Spieth and fellow American Bryson DeChambeau (65) are tied for second through 36 holes.
"It was a nice, positive start to the day and therefore I was able to get the momentum going on my front nine, which was the back nine, and actually played much better golf as the round went on and felt like I had opportunities to get in a little bit lower than I did".
Daily COVID-19 update reports 16 additional cases and 1 new death
For the first time, IN has now released a breakdown of COVID-19 by zip code. No new healthcare or community outbreaks were reported today.
Spieth has struggled for form - his last tournament victory came in 2017.
Harold Varner III opened with a triple bogey and closed with a flurry of five birdies over his last six holes to surge into the early second-round lead at the Charles Schwab Challenge in Fort Worth, Texas on Friday.
Gary Woodland, left, and Justin Rose, of England, almost touch fists on the 18th green following the third round of the Charles Schwab Challenge golf tournament at the Colonial Country Club in Fort Worth, Texas, Saturday, June 13, 2020.
Players also have to undergo temperature screenings, regular COVID-19 testing and practice social distancing on tee boxes and in the clubhouse.
Xander Schauffele chips to the 16th green during the third round of the Charles Schwab Challenge golf tournament at the Colonial Country Club in Fort Worth, Texas, Saturday, June 13, 2020.