Thornberry parlayed rounds of 67 and a 69 with an even-par final round of 70 to finish at 4-under 206 and win the boys' division of the Evitt Foundation RTC Junior All-Star tournament at WindStone Golf Club by three strokes while Daniel turned in rounds of 70, 73, and 72 for a 54-hole total of 5-over par 215 to claim the girls' division title by three shots.
The 10th Annual event, sponsored by the Ringgold Telephone Company, included 72 boys and 23 girls, ages 12-15, from 20 states along with Mexico and Canada. The boys' division played to a par of 70 at 6,352 yards with the girls' division playing to 5,658 yards.
Thornberry, a rising sophomore from Olive Branch, Miss., was playing in just his second career American Junior Golf Association Event.
"I felt really good with the course after playing a practice round," he said. "I got off to a good start (on Wednesday) and after that I knew I had a pretty good chance to win."
He sat in third place, just a shot behind first round leaders Mitchell Meissner (San Antonio, Tex.) and Terrence Zhang (Orlando, Fla.) after Tuesday. He moved up to second following Wednesday's round, just a stroke in back of Jalen Ledger (Palm Beach Gardens, Fla.), who moved from 10th place into the 36-hole lead after a second-round 65.
Things would remain tight for most of the day on Thursday, but Thornberry would take command in the final four holes. Ledger double-bogeyed the 15th hole while Eric Bae (Cary, N.C.) carded a double one hole later. A birdie at the par-5 17th hole suddenly gave Thornberry a three-shot lead headed to the 18th hole.
"I was just trying to hit fairways and greens and play my own game," Thornberry said after his final round. "I hit my driver well, and I putted pretty well so I knew if I could get some shots close, I had a good chance of making (the putts). It means a lot to get my first win. Hopefully I can win more."
Ledger and Issei Tanabe (Huntington Beach, Cal.) finished in a tie for second at 209 while Bae and Reid Rathburn (Alpharetta) posted three-day totals of 210 to tie for fourth.
Scott Stevens of Chattanooga had Thursday's low round with a 4-under 66 and finished eighth overall with a 4-over total of 214. Ben Rebne of Ringgold finished 70th in the field.
Daniel, a rising sophomore at Landmark Christian High School near Atlanta, was tied with fellow Newnan resident Annie Swords at even-par after the opening round and her 3-over 73 on Wednesday was enough to give her a one-shot lead over Kennesaw's Payton Schanen after 36 holes.
Schanen actually held a one-shot lead on the 17th tee, but her drive went into the woods, resulting in a bogey, while Daniel sunk a 12-foot birdie putt to flip the standings and take a two-shot lead over her friend going into the last hole.
Daniel then striped her tee shot down the center of the fairway to set up a steady par while Schanen hit her drive out of bounds to the left and eventually had to settle for another bogey.
"I tried not to let (having the lead) affect me, but at the beginning of the round, on the first few tees, I was kind of nervous," said Daniel, who finished 14th overall in this same event a year ago. "I bogeyed No. 2 and after that I knew I just had to keep pushing. It was nerve wracking but I had to push that aside and get over it to keep fighting.
It marked Daniel's fourth Top 10 finish in six career AJGA starts.
"It's really exciting to get the win because I have been practicing and preparing for this tournament," she added. "I played all last summer so it feels good to have a win."
Schanen would finish at 8-over 218 to take second by herself. Kaitlyn Papp (San Antonio) finished at 211 to take third, one shot ahead of Kaho Matsubara (San Diego, Cal.) and three ahead of Georgia native Megan Carter (Blackshear).
The top local girls' finisher was Katherine Holmes of Signal Mountain who shot a 239 to end up in 17th place.
The Evitt Foundation RTC Junior All-Star was one of 11 events in the Gary Gilchrist Golf Academy Junior All-Star Series. The Series will conclude with the Junior All-Star Invitational over Columbus Day weekend for winners and top finishers in the Series events.
"The tournament went really well, and zero weather delays which is always a plus," said Tournament Director Katie Tahara. "We had a great field and some tough competition to go with a great golf course and great sponsors. Having that kind of support in these events just helps us run a better tournament and give all the parents, players, and volunteers a better experience."