South Korea's Lee Kyoung-hoon joined legends Sam Snead, Jack Nicklaus and Tom Watson as the only players to successfully defend the AT&T Byron Nelson after a career-best 9-under 63 on Sunday earned him a thrilling one-stroke victory over hometown hero Jordan Spieth.

The 30-year-old, known as KH Lee on the tour, overcame a four-shot deficit at the start of the final round with seven birdies and one eagle to repeat as champion at TPC Craig Ranch near Dallas, Texas. His winning total of 26-under 262 was one stroke lower than last year's winning score which delivered his maiden PGA Tour triumph.

Spieth, chasing his 14th career title, closed with a 67 while Japan's Hideki Matsuyama ensured a strong Asian presence on the leaderboard with a stunning 62 pushing him up into a share of third place on 264 alongside overnight leader Sebastian Munoz (69).

"It's an amazing feeling. I can't believe it, it still feels like I'm dreaming, but last year and this year still make good memories," said a delighted Lee, whose parents, wife and baby daughter were greenside at the 18th to celebrate his second PGA Tour title.

The win was especially sweet the second time around. Just a month ago, Lee was struggling with his form following three successive missed cuts. Without a top-10 finish to his name this season, the Korean star went back to work recently with former swing coach Chris Mayson and a mental trainer. He also hired a new caddie, Dan Parratt, who previously worked with countryman An Byeong-hun, and reverted to using an old putter.

Lee now finds himself in an exclusive club at the Byron Nelson－a tournament which inaugurated in 1944－where only Snead (1957-58), Nicklaus (1970-71) and Watson (1978-80) have successfully repeated as champions.

"I heard that. It's amazing, I can't believe it," said Lee on his historic feat. "Just hopefully people remember my name, but yeah, I will try to play well more so hopefully more will remember my name."

Spieth needed to chip in for eagle on the last hole to force a playoff with Lee but missed. Afterward, he doffed his cap to Lee, having played alongside him in the first two rounds.

"I hit a shot that you don't practice into the green (on 18) and I actually thought I just stuck it and I don't know if I could have a thousand balls and hit it where I hit it," said Spieth.

"But I still had a chance, KH made a great par save on 17 and then went and hit the green in two on 18 and two-putted. He shot 8- or 9-under. We had it (the wind) blowing 15 to 18(mph, 24-28 kph) on our last 10 or 11 holes, so that score this afternoon, especially on the closing stretch of holes, is just a phenomenal score."