IRVING, Texas -- Walking down the 18th fairway during a playoff and realizing he was about to get his first PGA Tour victory, Keegan Bradley got emotional thinking about a cowbell.
The one that is in the World Golf Hall of Fame. The one his grandmother rang after every win by his famous aunt, LPGA Tour great Pat Bradley, whose 31 victories included six majors.
"It was like pull it together, don't start thinking about the cowbell," Keegan Bradley said. "The cowbell in my family is an iconic thing."
Bradley settled himself and won the Byron Nelson Championship, parring the first hole of a playoff with Ryan Palmer on Sunday. Bradley sank a 2-foot par putt at the 419-yard 18th hole in the playoff, while Palmer's approach went into the water before a 13-foot bogey putt.
Bradley, a PGA Tour rookie who never won on the Nationwide Tour, got his first professional victory nine days before his 25th birthday. He looked forward to talking to his aunt.
"She is a lot calmer on the golf course than she is watching me. I'm sure she was by the TV going crazy," Bradley said. "I talk to her regularly through text messages and phone calls about tournaments and what it's like to come down near the end. ... This is the closest thing we ever had in common in terms of playing."
About an hour before the playoff, Bradley finished his closing round of 2-under 68 with a par at No. 18, dropping into a squat and hopping a few times in frustration when his 10-foot birdie chance slid by the hole.
Palmer (72) and Bradley finished at 3-under 277, the highest winning score on the PGA Tour this year -- and the highest in relation to par in a non-major since 1999. It was the fifth playoff in six weeks and 10th overall.
Palmer forced the extra hole with a 6-foot putt at No. 18 for only the second birdie there all day. When that putt dropped, Palmer punched his right fist in the air and then raised both arms over his head.
Bradley and Palmer then played No. 18 again, both going way right with their tee shots to start the playoff.
Tournament volunteers quickly dismantled and moved a temporary lemonade stand to give Bradley, a Vermont native who played at St. John's, a line of sight to the green and avoid the necessity for a drop.
Bradley's approach was dangerously close to sliding off the side of the green into the water, but stayed up. Palmer went in the same direction but his ball didn't stay dry.
"I had a clear punch shot but it's so easy to hit it left when I'm trying to hit a punch like that, and it squared left a little bit," he said. "Then my putt, just wanted to tease myself a little more, I guess. But I got into the position to win the golf tournament and that's all I can ask for."
On the 172-yard 17th hole, Bradley sank a 12-foot par-saving putt and responded with an emphatic fist pump. After Bradley tapped in his par putt at No. 18, third-round leader Palmer was in one of the five groups still playing.
Bradley then sat for a few minutes before going to the practice range to prepare for a playoff that almost wasn't necessary for him to become the PGA Tour's sixth first-time winner this season.
"It was funny. I was really, really nervous and then when (Palmer) made the birdie I calmed way down," Bradley said. "I felt my heartbeat slow down. I calmed down."
Defending Nelson champion Jason Day (67) was fifth at 1 under, the last player under par this week at TPC Four Seasons. There were brutal scoring conditions, particularly for both weekend rounds when the wind was sustained at 25 mph with gusts howling near 40.
After Palmer blasted from a greenside bunker to 3 feet for a birdie at the 523-yard 16th hole to get back to 3 under, he gave that stroke right back when he missed a 7-foot par putt at No. 17.
Imada was 5 under after his 11-foot birdie putt trickled in at the 170-yard 13th, then blasted out of a greenside bunker to inside a foot at 14th to save par. He missed a 3-foot par chance at No. 17 and then was unable to save par again out of a bunker on the closing hole.
"Obviously I was a little nervous out there. I haven't been in that position in a while," said Imada, whose only victory was three years ago. "I didn't finish off like I wanted to, so it definitely leaves a sour taste in my mouth. But overall I played well."
Sergio Garcia, the 2004 Nelson champion who hasn't won since 2008 and hasn't locked up spots this year in the U.S. Open and British Open, began the day one stroke off the lead and in the final group.
Garcia missed a 4-foot par putt on the opening hole, then slammed his putter down on his bag walking off after his bogey putt. Things only got worse from there on way to a closing 77. He had a double bogey at the par-4 fourth hole after needing four shots to go the final 12 feet -- his first chip rolled back to his feet and he ended with a double bogey.
Day, the runner-up at this year's Masters, had his fourth top-10 finish in his last five tournaments.
After a bogey-free front nine with three birdies to get to 1 under for the tournament, Day was even par over a seven-hole stretch without a par on any of the holes. His birdie at No. 10 got him to 2 under before consecutive bogeys, a birdie, a double bogey and then consecutive birdies.
Bradley's playing partner was local teenage amateur Jordan Spieth, who had a rough finish. The 17-year-old player closed with two double bogeys and two bogeys for a 7-over 77 to finish at 6 over and tie for 32nd. That was 10 strokes higher than he shot last year at TPC Four Seasons, when he tied for 16th.