Billy Horschel claimed his fourth PGA Tour title by winning the AT&T Byron Nelson after getting the better of Jason Day in a play-off.

After both men finished locked on 12 under they had to play an extra hole and Horschel was victorious after Day missed a four-foot putt for par on the 18th.

It is first tournament win since 2014 and stops a rot after missing the cut at his previous four tournaments.

Horschel began the day a shot behind overnight leader John Hahn and battled through a tough round, making a one-under-par 69, which included a mammoth 60-foot putt for birdie on the 14th.

"This is the most emotional of all the four," he told Sky Sports. "The other three I was playing well going into them and this one I wasn't, I can't lie, I didn't have any success.

"I was a little shaky out there with the putter. I had a battle, I three-putted 12 and 13, which sure didn't do any help, but my birdie at 14 was the big turning point.

"Jason didn't have his bets game out there, and I know I didn't, but we both battled. This is what I know of myself. I am as good as the top players in the world. Do I have as much talent as Dustin Johnson and Rory McIlory? No, but I try to get everything out of my game that I can and if I can do that I can compete with these guys.

"I got a win today really not playing great so that goes a long way."

Day started his round one shot behind Horschel, but made that up with three birdies and two bogeys to card a 68.

Hahn's chances of winning were undone by three bogeys on the trot in the middle of the back nine, meaning he finished on 11 under with Jason Kokrak, who shot a career-best 62 on Friday, on 10 under.