IRVING, Texas, May 18, 2013 (AFP) - In windy conditions at the par-70 TPC Four Seasons Resort course, Bradley closed with a bogey for the third round in a row but the American still stood atop the leaderboard on 13-under 197 with Bae on 198 after a third 66 in a row.
"I'm playing really well," Bradley said. "I'm proud of how I played the last two days, and I'm happy with where I'm sitting."
Bradley won his first US PGA title at the 2011 Byron Nelson and went on to win the 2011 PGA Championship in his first major appearance.
Bradley could become first wire-to-wire winner at the Byron Nelson since 1980, when Tom Watson won the event for a record fourth time by capturing his third Byron Nelson title in a row. Mark Hayes also did it in 1976.
American Tom Gillis was third on 199 after concluding his round of 67 with a 45-foot birdie chip-in from a greenside bunker, with compatriot Scott Piercy fourth on 200 after a 66 that featured several long birdie putts.
"It was hard to get the ball close to the holes with those crosswinds," he said. "I was fortunate to be rolling it well. You just have to hit solid shots, reach the fairway and put it on the green somewhere."
South Africa's Charl Schwartzel, the 2011 Masters champion, was in a group sharing fifth on 202 that included Americans Harris English, John Huh and Gary Woodland. Australian Nathan Green was alone in ninth on 203.
Bradley sank an 11-foot birdie putt at the par-4 third but stumbled with back-to-back bogeys at the par-3 fifth and par-4 sixth, although he answered with birdies at the par-5 seventh and par-4 ninth.
Bradley sank a 34-foot birdie putt at the par-4 11th and added another at the par-5 16th, but stumbled again at the final hole.
After nearly finding water left off the 18th tee, Bradley was forced to pitch out from behind a rock into the fairway, then came up short of the green on his approach and ran his 24-foot par putt just past the hole.
Bae, who has won 11 times worldwide but has never won a US PGA event, began with back-to-back birdies before taking his lone bogey at the par-3 fifth. He added birdies at the par-4 eighth, par-3 13th and 16th to keep the pressure on Bradley.
Leading scores on Saturday after the third round of the $6.7 million US PGA Byron Nelson Championship (USA unless noted, par 70)
197 - Keegan Bradley 60-69-68
198 - Bae Sang-Moon (KOR) 66-66-66
199 - Tom Gillis 69-63-67
200 - Scott Piercy 66-68-66
202 - Gary Woodland 69-65-68, Harris English 64-70-68, John Huh 69-64-69, Charl Schwartzel (RSA) 63-70-69
203 - Nathan Green (AUS) 67-68-68
204 - D.A. Points 69-68-67, Marcel Siem (GER) 68-68-68, Martin Kaymer (GER) 68-67-69, Graham DeLaet (CAN) 67-67-70, Angel Cabrera (ARG) 65-69-70, Ted Potter 64-70-70
205 - Jerry Kelly 69-70-66, Cameron Percy (AUS) 68-68-69, Marc Leishman (AUS) 66-70-69
206 - D.H. Lee (KOR) 68-69-69, Justin Bolli 69-69-68, William McGirt 68-69-69, Charles Howell 67-69-70, Jimmy Walker 68-68-70, Charley Hoffman 68-68-70, James Driscoll 67-72-67, Camilo Villegas (COL) 65-70-71, Martin Flores 67-68-71, Jason Day (AUS) 72-68-66, Stephen Ames (CAN) 67-68-71, Ryan Palmer 65-68-73, Morgan Hoffmann 69-71-66