Perry had matching 33s Saturday, with six birdies and one bogey.
SCOTTSDALE, Ariz. (AP) -- After erasing a four-stroke deficit in five holes, Kenny Perry wanted to be alone atop the FBR Open leaderboard.
All it took was a 33-foot putt on the 18th hole Saturday. When the putt dropped into the cup, it brought a roar from the massive TPC Scottsdale gallery and gave Perry a one-stroke lead over Scott Piercy through three rounds.
"Good time to make one," said Perry, who shot a 5-under 66.
Despite stumbling down the stretch, Piercy thought he had a one-stroke lead when he reached the clubhouse.
"They've still got to catch me right now," Piercy said after his 66.
Perry already had.
Perry erased a four-stroke deficit between the 13th and 17th holes. He birdied the 17th to catch Piercy and birdied the 18th to surge past him.
"Supper's going to taste good tonight," Perry said. "Great day."
Kevin Na (66), Brian Gay (67) and Charley Hoffman (69) were tied for third, two strokes off the lead.
Perry's rally set up an intriguing Sunday duel between Perry, who turned pro in 1982, and Piercy, a rookie.
The 48-year-old Perry has 12 tour victories. The 30-year-old Piercy is playing in his 23rd PGA Tour event, and he's here on a sponsor exemption.
Na will join Perry and Piercy in the final group.
Perry's rally actually began Thursday, after he struggled through the first 14 holes.
"I was out of here," Perry said. "I'm 4 over with four to play on Thursday and just pretty much mad, basically, going into 15."
But Perry smashed a 3-wood from 275 yards out and birdied the par-5 15th, and he's been rolling ever since.
"You know what, it's amazing what one shot can do for you in a tournament," Perry said. "You can either go one way or another with one golf shot."
Counting the 15th, Perry has an eagle, 16 birdies and only two bogeys in the 40 holes since that shot.
Perry is playing with an added personal burden.
His father has had two stents put in his heart. His mother has blood cancer and is in an assisted-living facility. And his wife's mother fell at a fast-food restaurant, breaking her knee cap and two vertebrae.
"It's been a tough time, a tough go for us," Perry said this week. "We just need to figure out some way to get us through this winter, and hopefully they're going to come out of this deal."
Piercy burst onto the scene two years ago in Las Vegas, when he erased a three-stroke deficit in the last five holes to win $2 million in The Ultimate Game.
Piercy said that experience, and years of Monday qualifying, have steeled him for his first full season on the Tour.
"I think the thing I'll draw from is the fact that when the pressure is on, I know I can get it done," Piercy said. "When it's hot in the kitchen, I like to be there."
It got hotter for Piercy as the sunny, 74-degree afternoon wore on.
Piercy started the day in a tie for eighth at 6 under. He quickly vaulted to the top of the leaderboard with birdies on eight of the first 13 holes.
"The putter was rolling so well today," he said. "The hole looked like a five-gallon bucket."
Piercy's lead over Perry grew to four strokes after 13 holes. But that's when Piercy began to falter.
On the par-4, 477-yard 14th, he buried his second shot in thick grass beyond the green, then fluffed his chip shot and two-putted for bogey.
The 558-yard 15th had been the easiest hole this week. But Piercy drove into a lake on the left and took another bogey.
At some point, Perry glanced at a leaderboard and saw that Piercy had dropped to 11 under from 14 under.
"I was like, 'What happened?' " Perry said. "So either they put wrong numbers up or he had a couple of tough holes coming in."
Piercy missed a chance to make up a stroke on the fully enclosed 16th. Piercy hit his tee shot to five feet but missed the birdie putt and had to settle for par.
Piercy followed that with another bogey, on the par-4, 332-yard 17th -- his third bogey in four holes.
Piercy parred No. 18, but by the time he reached the clubhouse, his lead over Perry had evaporated into the dry desert air.
Piercy said he didn't look at his slow finish as a missed opportunity.
"The bogeys, whatever," Piercy said. "I look at it as eight birdies; that was awesome."