Langer had five birdies and a bogey at Carnoustie's Championship Course in his 67. Jay Don Blake and Carl Mason also turned in 67s. Dan Forsman, Bruce Vaughan and Mark Wiebe are tied for fourth at 3-under 68 with another six golfers at 2-under.
Langer opened with a birdie and had three consecutive birdies to close in front nine. He added another birdie at 14 but a bogey at the 15th left him at 4-under.
"I'm very happy with it," Langer said. "I played very well. I kept the ball in play, I drove it pretty good and hit a number of fairways. When I didn't hit the fairway, I was either fortunate enough to get a reasonable lie or miss some trouble and hit those shots out of the rough pretty good. Made a few putts and hit my irons fairly close."
Blake had six birdies and two bogeys, including one at the 18th hole that cost him the outright lead.
Mason had four consecutive birdies from 3-6 but also took a 6 on the par-4 10th hole. He added birdies at 12 and 14 but a bogey at 15 -- the same hole that tripped up Langer -- returned him to 4-under.