Sweden's Peter Hanson will take a one shot lead into the final round of the Masters after posting a seven-under par round of 65 at Augusta National on Saturday.
The 34-year-old made a late charge up the leaderboard with birdies at four of the last five holes to eclipse the efforts of home favorite Phil Mickelson.
The three-time Masters champion was also in scintillating form on the back nine taking just 30 strokes.
Birdies at the par four 10th and the par-three 12th were followed by an eagle at the par five 13th which sent the Augusta crowd into raptures.
Further excitement followed at the 15th as Mickelson claimed a birdie four with another coming at the 18th to leave the 41-year-old on eight-under par and in pole position to claim the fifth major title of his career.
South Africa's Louis Oosthuizen is one shot further back after a composed round of 69 while playing partner England's Lee Westwood had to settle for an even-par round of 72 which leaves him in a tie for sixth on four-under par with Sweden's Henrik Stenson (70).
America's Hunter Mahan and Ireland's Padraig Harrington are also four-under after both men shot rounds of 68 on Saturday.
Bubba Watson continues to creep up the leaderboard after another sub-par round (70) moved him up to fourth place. Compatriot Matt Kuchar also shot 70 to finish one shot further back on five-under par.
Overnight leaders Fred Couples and Jason Dufner couldn't keep pace with the fireworks of the leaders. Both men finished with three-over par rounds of 75 to drop into an eight-way tie for 11th place.
Rory McIlroy is out of the running after posting a third round 77.
A double bogey at the first was the first of six dropped shots on the opening nine with another coming at the long par-four 11th.
The Northern Irishman clawed back a couple of shots, and nearly holed his approach to the 18th, but at one-over par for the tournament is too far back to mount a challenge.
His playing partner, Spain's Sergio Garcia also had a disappointing day posting a three-over par 75 to leave him one-under after three rounds.
Tiger Woods is also out of contention after another even par round of 72 left him 12 shots off the lead.
"I didn't play that badly. It was so close to being a really good round of golf. I did not play the par-fives that well. I just didn't take care of the opportunities when I had them," Woods said.