Former champion Bernhard Langer moved into contention to become the oldest major champion by a decade as Rory McIlroy suffered more Masters misery on Saturday.
Langer, who won the second of his green jackets three months before defending champion Jordan Spieth was born, utilised all of his experience to card a third-round 70 despite the windy conditions at Augusta National.
That left the 58-year-old just one shot off the clubhouse lead held by Smylie Kaufman and in contention to surpass the 48-year-old Julius Boros as the oldest winner of any major. Jack Nicklaus was 46 when he became the oldest Masters champion in 1986.
"I've been saying it's going to happen sooner or later," Langer told CBS. "W e have guys like Davis Love, Vijay Singh and Fred Couples who are all long enough to win majors.
"I'm not in that category but I try to make up for it in others and tomorrow I'm going to give it my best. That's all I can do."
McIlroy has a weekend scoring average at Augusta of 68.5 in the last two years, but that was certain to rise as the world number three, looking to win the Masters to complete the career grand slam, slumped down the leaderboard.
Spieth, who is looking to become only the fourth player after Jack Nicklaus, Nick Faldo and Tiger Woods to win back-to-back Masters titles, began the day with a one-shot lead into the round and edged further in front thanks to a two-putt birdie on the par-five second, where McIlroy missed from eight feet having being forced to lay up from a fairway bunker.
It looked as though Spieth would give the shot straight back when he drove wildly into the trees on the third, but he punched out to the back of the green and got up and down for par, and instead it was McIlroy who bogeyed after his approach from a fairway bunker span back off the green and he failed to get up and down.
McIlroy sensed a great chance for a two-shot swing on the seventh with Spieth struggling to make par after driving into the trees and finding sand with his approach, but the Northern Irishman three-putted from 25 feet and saw his playing partner scramble a matching five.
Spieth was nowhere near the form which saw him set records for the most birdies (28) and lowest 36 and 54-hole totals last year, but was grinding out a score and birdied the eighth after pitching to four feet.
McIlroy had found another fairway bunker off the tee and had to settle for par to fall four behind, and then brought back memories of his collapse in 2011 by hooking his drive into the trees on the 10th.
Although the ball bounced out towards the fairway, the resulting bogey dropped him further behind and the 26-year-old's chances then looked to be over when he found water with his approach to the 11th after a risky second shot from the pine straw, only for Spieth to also make a double bogey after taking four to get down from short of the green.
Spieth bounced back with a birdie from 17 feet on the 12th before McIlroy missed from half the distance, with both players then failing to birdie the par-five 13th.
At four under par Spieth was two shots ahead of Kaufman, whose 69 was the first sub-70 score since Thursday, and Japan's Hideki Matsuyama, who had two holes to play.
World number one Jason Day was a shot behind playing partner Langer after a 71 left him on level par alongside Dustin Johnson, with McIlroy not completely out of contention on two over.