Langer, who had been two strokes in front overnight, reeled off four birdies in five holes from the 12th to regain control of the tournament before ending the day with a 15-under total of 195.
American Perry, who won last year’s Senior Players Championship by two shots at Fox Chapel, was alone in second at 12 under after carding a sizzling 65 that included an eagle at the par-five second and six birdies.
Perry, who clinched his third consecutive major on the Champions Tour with victory at the Regions Tradition in May, had been one ahead with four holes to play but slipped back with a bogey at the 16th before the fast-finishing Langer took charge.
Left-hander Russ Cochran (63) and fellow Americans Joe Durant (67) and Bill Glasson (68) were tied for third at 11 under in the third of the year’s five senior major championships.
Langer, whose previous major wins on the Champions Tour came at the 2010 Senior Open Championship and the 2010 U.S. Senior Open, is taking nothing for granted with several quality players in close pursuit and 18 holes to be played on Sunday.
“There are about 10 other guys within striking distance,” the German, a twice former Masters champion, told reporters after moving back to the top of the leaderboard with birdies at the 12th, 14th, 15th and 16th. “It’s not over by any means.
“Kenny played very well here on this golf course last year.
“I played with him the first two days, he played very well. He drives the ball very far and pretty straight, which sets himself up pretty good.
“I’ve still got to shoot under par. Somebody shot seven-under today I think, right?” Langer asked in reference to Cochran’s 63.
“So anybody that is 10-under, 11-under, shoots that kind of score, I’ve got to go under-par. Still 18 holes to play, it’s a lot of golf.”
Langer has won two Champions Tour events this year, the Mitsubishi Electric Championship at Hualalai and the Insperity Invitational, and will be seeking his 21st career title in Sunday’s final round.
Perry, who trailed Fred Couples by two shots heading into the final round at Fox Chapel last year before charging to victory with a closing 64, embraced the feeling of deja vu.
“It’s kind of running just like last year,” the 53-year-old smiled. “I just hope the results are the same.
“Bernhard is a different character. He’s tough. He’s gritty. He’s got a lot of heart. He’s a good friend and I enjoy competing against him.
“I am looking forward to the challenge tomorrow … I need to shoot seven-under probably.”
(Reporting by Mark Lamport-Stokes in Los Angeles; Editing by Greg Stutchbury)