Bernhard Langer fired a 6-under 64 on Saturday to grab a 4-stroke lead after three rounds of the U.S. Senior Open.
Langer, the 2010 champion, finished 54 holes at 10-under-par 200. He missed the 54-hole scoring record by two strokes.
The German has finished second twice this year, and hasn't won since February 2011.
Tom Pernice, Jr. carded a 4-under 66 to move into a share of second place at minus-6. He was joined there by Tradition winner Tom Lehman, Senior PGA Championship victor Roger Chapman, John Huston and Corey Pavin, who all shot 68 in the third round on the Old Course at Indianwood Golf & Country Club.
Fred Couples, the 2010 runner-up, fired a 5-under 65 to finish 54 holes tied at 5-under-par 205. He stands alongside 2009 champion Fred Funk (67), Jay Haas (68) and Dick Mast (69) in seventh place.
Second-round leader Lance Ten Broeck struggled to a 2-over 72 to dip into 11th place at 4-under-par 206.
Langer was two back to start the day, but quickly made a move. He poured in a 20-footer at the first and made a 35-foot birdie chance on the second. That gave him a share of the lead.
The 54-year-old made it three in a row as his 20-foot birdie putt at the third found the bottom of the cup. After a pair of pars, Langer ran home a 25-foot birdie putt at the sixth.
Langer poured in another long birdie chance at the seventh to get to 9-under. He made the turn with a 3-stroke lead, and extended that even further early on the back nine.
He converted back-to-back 5-footers at 10 and 11 as he got through the first 11 holes with just 15 putts.
Langer sank an 8-footer for birdie on No. 12 to make it three in a row. He was five clear at that point, but trouble loomed.
After coming up short at the par-3 13th, Langer hit a poor chip. He pitched his third within four feet, but 2-putted for a double-bogey, which dropped him to 10-under.
"Hoping to go really low and then made an error on No. 13. Really wasn't that bad a shot with the 4-iron," Langer said. "Just hit it a little high on the club and came up two yards short in the rough and hit a bad chip shot and a bad short putt and made double-bogey."
Langer got one stroke back with an 18-foot birdie putt at the 15th. He three- putted for a closing bogey, but was still three strokes clear of the field.
"The only difference really was just I made some putts. I probably played worse than I played the first two days," Langer admitted. "The first two days I made very little, and I guess the course owed me some. I made a bunch of putts today."
Pernice started with birdies on one and two before running off eight straight pars from the third. He had three birdies in a six-hole stretch from the 11th to move to 7-under. However, Pernice tripped to a bogey at the last.
Lehman wrapped birdies at one and three around a double-bogey on the second. He also birdied the ninth to make the turn at 5-under. Lehman's back nine included eight pars and a lone birdie on the par-4 12th.
"Not the best start, but it was an erratic day from beginning to end. Either hit a really good shot or hit a very poor shot," said Lehman. "But I got a lot of nice recoveries. So when it's all said and done, I escaped really with a decent score from a very poor round."
Chapman parred the first eight holes, before making a birdie on the ninth. He made it two in a row with a birdie on the 10th, but bogeyed each of the next three holes to slip back to minus-3. Chapman rallied with three birdies in his last four holes to share second.
Huston birdied the first and 14th. In between, he cruised to 12 consecutive pars. After faltering to a bogey at the 16th, Huston birdied the last to end at minus-6.
Pavin had a pair of birdies on the front nine, but couldn't keep pace as he played the back nine in even-par. He birdied the 10th to move to 7-under, but dropped a shot on the 14th to slide into a share of second.
NOTES: Defending champion Olin Browne posted a 70 and is tied for 38th after three rounds at 3-over-par 213...Doug Hanzel (plus-4) and Sean Knapp (plus-8) were the only two amateurs to make the cut...Russ Cochran withdrew before the round due to a back injury.