Mark Wiebe fired a 5-under-par 65 on Friday to grab a share of the lead with Bernhard Langer through two rounds of the Senior British Open.
Langer, who has two Champions Tour wins this season and 18 in his career, shot 67 at Royal Birkdale Golf Club to hit the clubhouse with the lead. Wiebe then birdied four of his final six holes to catch the German at 5-under-par 135.
David Frost, also a two-time winner on the circuit this season, carded a 2- under 68 and dropped a place to third at 4-under 136 through 36 holes.
"The club felt a little clumsy in my hand today," Frost said in a televised interview. "It just wasn't feeling comfortable ... but luckily the timing with the putter was there."
First-round leader Gene Sauers fell into a tie for fourth place courtesy of a second-round 70. He is joined at 3-under by Peter Fowler (68) and Mark McNulty (67).
Rocco Mediate, who won the Allianz Championship in February, shot 68 and moved into a share of seventh place with Sandy Lyle (68) and Jeff Hart (69). That group sits at minus-2, one stroke ahead of this season's Senior PGA Championship winner Kohki Idoki (68), Peter Senior (71) and Greg Turner (69).
Frost held the lead for much of Friday's action courtesy of a bogey-free outward 31, which featured birdies at the second, fifth and ninth.
The 53-year-old was up by two over clubhouse leaders Sauers and Fowler at the turn, but he found a greenside bunker at the 12th and stumbled to a bogey, then dropped another shot at the 14th to fall into a share of the lead at 3- under.
Langer, playing a group behind, promptly joined the leaders with a birdie at the 13th. He was even-par on his round prior to that point, mixing birdies at the fifth and eighth with a double-bogey 6 at the sixth, a hole which he bogeyed in the opening round.
Langer moved into sole possession of the lead at 4-under with a birdie at the 15th, then matched Frost's gain at the 17th, landing his approach within 12 feet and draining the putt to stay a stroke ahead.
"I've been hitting a lot of fairways, giving myself opportunities to attack certain pins or at least get the ball on the green and make par," said Langer.
When Langer parred the last to hit the clubhouse at 5-under, Wiebe was one of the few remaining players on the course.
Going out in the fourth-to-last group, Wiebe played his outward nine at 1- under with a pair of birdies and a bogey at the sixth.
Around the turn, Wiebe parred three straight before gaining momentum down the stretch with a birdie at the 13th. He turned the trick in succession from the 15th, then added one more birdie at the last to join Langer on top.
NOTES: This season, Langer won the ACE Group Classic in February and the Greater Gwinnett Championship in April ... Wiebe is a three-time Champions Tour winner ... Kenny Perry, who has won the past two tournaments on the Champions Tour (both majors), is skipping this tournament ... Defending champion Fred Couples is 6-over-par 146 through 36 holes ... Tom Watson, the 2014 American Ryder Cup captain, is 4-over-par 144 ... The cut line fell at 8- over, with 74 players making it through to the weekend ... Bob Gilder, who extended his record streak of consecutive major championship starts on the Champions Tour to 63, failed to make the cut at 13-over.