DALLAS -- Aaron Wise had to kick his mom out of his hotel room because she was too chatty during a four-hour rain delay before his best shot at a first PGA Tour victory.
The 21-year-old rookie's caddie had to snap him back into the moment when Wise worried if he would get to finish the AT&T Byron Nelson as daylight faded with a comfortable lead over the final holes.
Wise didn't have to wait an extra 12 hours to celebrate, and mom got a twilight hug after a tap-in and another wave to the thinned-out crowd on the 18th green at the new Trinity Forest course.
Pulling away at the turn after the long delay to start the final round Sunday, Wise shattered the tournament record at 23 under with a closing 6-under 65 to beat Marc Leishman by three strokes as both became the first to finish the Nelson at 20 under or better.
"I did a great job of staying focused on the present today," said Wise, who won once each on the Web.com and Canadian tours. "That was a big key for me winning. My mom, my girlfriend, my girlfriend's family, a bunch of my other family was there.
"Mainly my mom and girlfriend were the two I wanted to hug and appreciate that time with."
Leishman, who shared the third-round lead with Wise after leading the first two days, shot 68.
The treeless links-style par-71 layout, a few miles south of downtown Dallas, was defenseless with softer fairways and greens and little wind once the morning storms passed.
The Nelson celebrated its 50th anniversary with a return to Dallas after 35 years at the TPC Four Seasons in suburban Irving. Rory Sabbatini set the previous record on that par-70 layout at 19-under 261 in 2009.
"I felt like when it rained today I was really going to tear the course up just because it allowed me to hit driver, which is my strength," said Wise said, who was born in South Africa but raised in the U.S. "I got a lot of short irons in my hand and was able to make a lot birdies."
Branden Grace holed a blind bunker shot for birdie on the par-5 first and matched his career-best 62 from last year's British Open -- which was the lowest round ever in a major. He finished at 19 under with J.J. Spaun and Keith Mitchell, who had matching 63s.
Hometown star Jordan Spieth again couldn't improve on his best Nelson finish from his first start as a 16-year-old amateur in 2010. The three-time major winner, and highest-ranked player in the field at No. 3, shot 67 to finish at 11 under. Spieth tied for 21st.
Instead, Spieth has been joined by another 21-and-under winner, with Wise cruising a month shy of his 22nd birthday and two weeks after the 2016 NCAA individual champion at Oregon tied for second at the Wells Fargo Championship, two shots behind Jason Day.
Spieth doesn't have a top 10 finish in eight Nelson appearances, the most of any tournament for him.
"Felt like I played better than I scored," Spieth said. "Typically when you say that, it just means putts didn't go in."
Mitchell, also a rookie seeking his first win, and Ryan Blaum had matching 30s on the front nine, with both playing the last six holes on that side in 5 under. But Wise had five birdies over those six holes, and added one on the 10th while Leishman bogeyed.
His lead suddenly at four shots, Wise cruised from there with all pars -- and that was plenty in his second bogey-free round of the week.
Leishman set a 36-hole Nelson record that was previously shared by Tiger Woods because of calm wind the first two rounds. A blustery Saturday brought scores up, but Trinity Forest was even more benign for the final round than it was the first two without its firm fairways and greens.
"It would have been windy I probably would have preferred that, firm and windy, taken a few of the guys behind a little more out of it," Leishman said. "You get what you're given. You can't choose your conditions. I played pretty good. He played better."
Adam Scott shot 65 to tie for ninth at 15 under but was projected to be just outside the top 60 in the world rankings, which he needed to avoid sectional qualifying for the U.S. Open. The 2013 Masters champion hasn't missed a major since 2001.
"I was kind of hopeful to get up there a little bit more but I mean I don't even think it's going to get there now," Scott said. "It's too easy out there, soft and got hundred yard-wide fairways. It's hard to get in trouble."