|-23 J Day (Off); -22 K Si-woo (Kor), A Eckroat (US); -21 CT Pan (Tpe); -20 S Scheffler (US), T Hatton (Eng), Z Dou (Chn)
|Selected others:-16 S Power (Ire); -13 M Laird (Sco)
Jason Day claimed his first PGA Tour title in five years by winning the Byron Nelson in Texas.
Day, 35, shot a nine-under final round of 62 to finish 23 under overall, one stroke ahead of Kim Si-woo of South Korea and American Austin Eckroat.
Australia’s bogey-free round featured a brilliant chip-in for birdie on the 12th hole.
This is the former world number one’s 13th PGA Tour title but first since the 2018 Wells Fargo Championship.
“It’s been a struggling few years, five years since our last win,” said Day, who won the 2015 PGA Championship.
“The way I’m playing today is very special. I’m very happy and pleased with how things have progressed in the last two years.”
Day said it was “hard to just try to get through a tournament” because of back injuries in the years since his last win.
He added: “To be on the other side of it, to be healthy, to win again. It’s great to be on the other side.”
Day won his first PGA Tour title at the 2010 Byron Nelson, then held another course in Dallas.
He began the final round at TPC Craig Ranch in McKinney in a tie for fourth, two shots behind the leading trio of Eckroat, Ryan Palmer and Zecheng Dou.
He hit four birdies on the front nine to move within a share of the lead, clinching it with his sublime chip at the 12th.
Kim, who fired a good round of 63, birdied the final hole to move to 22 under, where Day knew he also needed to find a birdie to avoid the play-off.
An excellent tee shot gave Day a simple two-foot birdie chance which he converted to take the clubhouse lead.
His victory was confirmed when Eckroat missed an eagle at the end.
Day will be looking to win his second major title when this year’s PGA Championship in New York begins on Thursday.
World number two Scottie Scheffler, who started the final round level with Day, threatened with four birdies on the front nine.
But he couldn’t keep up the pace, carding a six-under 65 to finish in a tie for fifth with England’s Tyrrell Hatton and China’s Dou.