Jordan Spieth missed out by a shot as Korean KH Lee fired a brilliant final-round 63 to complete a successful but unexpected defence of his AT&T Byron Nelson Classic crown.
With the birdies flying in again at TPC Craig Ranch in Dallas, Spieth stuttered at the start when opening bogey-birdie-bogey.
He then became part of a crazy eight-way tie for the lead after four birdies in five holes to the turn but a homeward 2-under 34 and a final lap of 5-under 67 meant he ended the day the way he started it: one shot back from the leader.
Spieth, a Dallas resident, said: "I love playing at home, I would love to win it some day. I had a good chance here.
"But it was a good week, good momentum into next week, last two starts being a win and a second, but this one will sting just a little bit just looking back on the day."
Lee went to the turn in 31 and then started to take control of the tournament with an eagle-birdie run at 12 and 13.
A closing birdie at the par-5 last after finding the green in two kept his rivals at bay and gave him a winning total of 26-under 262, a shot better than 12 months ago when he won by three from Sam Burns.
Lee joined legends Sam Snead, Jack Nicklaus and Tom Watson as the only golfers to successfully defend the AT&T Byron Nelson.
"It's amazing feeling. So I can't believe, still feels like dreaming, but last year and this year still make good memories," said a delighted Lee after claiming his second PGA Tour title.
Hideki Matsuyama stormed through the field to take third place alongside 54-hole leader Sebastian Munoz. The pair finished two back.
Matsuyama fired a brilliant 62 while Munoz (69) couldn't make enough birdies to hold on.
Xander Schauffele shot the low round of the day, an 11-under 61, to share fifth with Ryan Palmer and Justin Thomas.
The Texas angle shows up again
It's notable how many players with Texas connections perform strongly when the PGA Tour visits the Lone Star state.
Lee was the defending champion so both his wins have come in Texas while local hero Spieth now has two wins and six second places in his home state.
Third-placed Munoz lives in Texas and went to college there while Palmer (T5) is a born-and-bred Texan.
Fate of the favourites
With the PGA Championship taking place in Tulsa this week, the big names were hoping to get a good run under their belts.
Spieth certainly did that, as did Justin Thomas even though both will be disappointed not to have won the winner's cheque.
Pre-tournament favourite and World No.1 Scottie Scheffler didn't quite do enough but tied 15th was a decent way to keep ticking over.
But it wasn't ideal prep for everyone.
Dustin Johnson is still trying to find his best stuff and tied 59th here suggests the search goes on while Will Zalatoris and Sam Burns both missed the cut.