Jordan Spieth hasn't played much golf lately.

The three-time major winner revealed this week that he tested positive for COVID-19 about 10 days after the Masters, leading him to take a few weeks off to recover. Yet his bout with the coronavirus sapped neither his golf talent nor his flair for thedramatic.

Spieth drained a 55-foot eagle putt on the final hole to cap off a bogey-free, 9-under 63 and vault himself into a tie with J.J. Spaun for the first-round lead at the ATT Byron Nelson on Thursday.

TPC Craig Ranch, in the Dallas suburb of McKinney, Texas, is hosting the Byron Nelson for the first time. Despite the venue change, Spieth, a Dallas native, made himself at home -- once he shook off some unusual first-tee jitters.

"I had nerves on No. 1 like it was the first shot of the season," Spieth said. "I didn't practice for three weeks straight, which is very unusual. Normally two days off is the most during a season."

He said sinking a 12-foot birdie putt on the first hole was an important confidence-builder as he got settled in. Spieth followed that up with four more birdies on the front nine.

His tee shot on the par-5 12th sailed far right of the fairway into some thick rough. Rather than laying up, Spieth cut a hybrid right at the flag. His 247-yard shot rolled off the back of the green onto an elevated lip, trickled back down and settled inside 10 feet, where he two-putted for birdie.

That would have been his best shot of the day had he not made his eagle chance on No. 18. Putting from a lower tier of the green up a severe slope, Spieth judged the speed perfectly.

"It's one I'm just trying to get to tap in and cap off a good day," Spieth said. "I started leaning because I thought it was gonna miss left and it just kind of fell in the left side of the hole. The roar was pretty electric."

A 12-time PGA Tour winner, Spieth has yet to win the Byron Nelson. However, he did claim victory at the Valero Texas Open at TPC San Antonio in April, the week before the Masters, which ended a nearly four-year winless drought.

Spaun also finished without a bogey, and he holds at least part of the lead at a PGA Tour event for the third time in his career. He has yet to earn a win.

After starting on the back nine, Spaun wrapped up on No. 9 with a birdie to eke ahead of the pack early in the day.

Spaun has missed nine of 16 cuts this season but came to Dallas off an encouraging showing at last week's Wells Fargo Championship, where he tied for 18th. The 30-year-old said he'd been "spinning (his) wheels" trying to fix his game, but soon stopped himself from overthinking things.

"It was a lot of searching," Spaun said, "and I feel like that's something that us golfers kind of do too much of when things start to go wrong, instead of just chalking it up to a bad week or a just kind of a couple-week slump with the striking."

Spain's Rafa Cabrera Bello and Americans Doc Redman, Aaron Wise and Joseph Bramlett are in a tie for third after shooting 8-under 64. A group of 12 golfers -- two-time Byron Nelson champ Sergio Garcia of Spain and former world No. 1 Luke Donald of England among them -- are at 7 under.

Thursday was marked by favorable scoring conditions. Of the 156-man field, only 12 shot over par.

Defending champion Sung Kang of South Korea is in a tie for 34th at 5 under.

Masters champ Hideki Matsuyama of Japan, in his first tournament back since his first major victory, opened with a 4-under 68, tying him for 54th.

--Field Level Media