Jeff Maggert is the surprise leader after the third round at Augusta after a 66 which has taken him to five under.
-5 J Maggert
-3 M Weir
-2 V Singh
-2 D Toms
-1 P Mickelson
-1 T Woods
-1 JM Olazabal
Canadian Mike Weir, the second round leader, struggled to a 75, while Vijay Singh, Tiger Woods and Phil Mickelson are all in contention.
The key action as it happens (all times BST):
0011: Mike Weir finishes with a par and a round of 75 - he will partner Maggert in the final pairing in Sunday's climax.
0001: Phil Mickelson holes a superb putt to par the last and will start his second round at one under.
2359: Mike Weir bogeys the 17th to fall to three under - Jeff Maggert's lead is now two shots.
2345: Jose Maria Olazabal finishes with a par and he too is at one under for the tournament. Mike Weir bogeys the 16th to lose his share of the lead.
2336: Tiger Woods finishes with a par for an outstanding round of 66 which will make his final day a very interesting one.
2335: Mike Weir birdies the 15th to share the lead with Jeff Maggert.
2331: Vijay Singh finishes his round with a bogey but his total of two under will put him firmly into contention for the final round. Phil Mickelson birdies the 15th to get to two under.
2323: Jeff Maggert's incredible birdie run continues at the 18th as he posts a three-round score of five under and takes the lead.
2320: Jose Maria Olazabal, a two-time winner at Augusta, birdies the 16th to get to one under.
2309: Jeff Maggert birdies the 17th for a share of the lead, while his playing partner David Toms moves to two under.
2307: While the standard has picked up at the top of the leaderboard, spare a thought for Darren Clarke who takes a nine at the par five 13th and is completely out of contention.
2305: Mike Weir bogeys the 13th and his lead is down to just one shot, with Vijay Singh making birdie at the 16th.
2302: Tiger Woods moves to one under after a tap-in for a birdie at the seventh - the 16th hole of his round.
2257: Vijay Singh moves closer with a birdie at the 15th, courtesy of a chip-in from 20 yards.
2255: Jeff Maggert birdies the 16th to cut Mike Weir's lead to two shots. At the same moment, the leader puts his second shot at the 13th into Rae's Creek.
2251: The intimidating figure of Tiger Woods is firmly in the sights of the leading players as he birdies the sixth to get to even par, the target he set himself at the start of the round.
2248: David Toms birdies the 15th to move to one under, after a run of three birdies in three holes.
2244: Ernie Els' mixed round ends with a 10-foot par putt and a round of 72, which leaves him at one over par for the tournament.
2235: Jim Furyk finishes his round and holds the clubhouse lead at level par for the tournament.
2233: Leader Mike Weir drops a shot at the 11th while Ricky Barnes suffers a double bogey at the 12th.
2231: 'Amen Corner' will be something Paul Lawrie will want to forget about - after a double bogey at the 12th he suffers a triple-bogey at the 13th and is eight shots off the lead.
2226: Jeff Maggert holes a tremendous breaking putt to move to second place.
2222: Amateur Ricky Barnes suffers a bogey at the 11th to drop back to one under.
2216: Jeff Maggert birdies the par five 13th to join the group at one under.
2214: Vijay Singh birdies the 12th to move back to one under.
2207: Paul Lawrie's excellent round takes a turn for the worst as he puts his tee shot into the water at the 12th and suffers a double bogey.
2202: Tiger Woods continues his excellent progress with a birdie at the second - his 11th - to get to one under. Another player improving is Jim Furyk, who birdies the 16th to return to one under.
2156: Weir bogeys the ninth to move back to six under, with a comfortable lead of four shots still.
2152: A double bogey at the 11th takes American Jeff Maggert out of the chasing pack and back to level par.
2147: Bogeys for Phil Mickelson and Ernie Els move them further behind. At the same time, amateur Ricky Barnes continues his astonishing form by making a birdie at the ninth.
2141: Darren Clarke ends his terrible start with a birdie at the seventh.
2137: Jeff Maggert creeps into joint second place with a birdie at the 10th.
2133: Ernie Els, who fell foul of the 13th hole last year during his final round, makes a mess of things this year as well, a bogey six dropping him back to level par.
2125: Mike Weir birdies the sixth to move to seven under, a five-shot lead. Another leftie, Phil Mickelson, birdies the eighth to move to one under.
2123: Paul Lawrie holes a 25-foot putt at the ninth for par to remain at two under.
2122: Jim Furyk puts his second into Rae's Creek at the 13th and bogeys the par five to drop back to level par.
2113: Weir completes a tricky up-and-down to remain at six under. But it is another miserable hole for Darren Clarke, whose bogey takes him to one over.
2103: Weir bogeys the fifth to fall back to six over, while a bogey for Clarke takes him to level par.
2054: Tiger Woods makes his third birdie of the day to get to two over.
2049: Paul Lawrie goes into second place on his own with a birdie at the seventh.
2044: Lawrie joins the pack at one under with a birdie at the sixth. Woods birdies the 13th to get to three over.
2020: Leader Weir birdies the second hole while Clarke bogeys the same hole, giving the Canadian a seven-shot advantage over the rest of the field.
2013: Phil Mickelson and Ernie Els pick up birdies to get to one under - five players are tied for third at that score.
2006: American Jim Furyk moves further up the leaderboard with a birdie at the eighth to go to one under.
2001: The top two, Mike Weir and Darren Clarke, complete the first hole - with 49 players on the Augusta National, only four are under par.
2000: Is the Tiger finally going to roar - the world number one birdies the 11th to join the big group at four over. At the same time, world number two Ernie Els picks up a birdie to get to level par.
1955: Phil Mickelson begins his third round with a bogey to move back to level par.
1950: The first player to move into minus figures is 2000 winner Vijay Singh, who birdies the second to move into a tie for third at one under par.
1948: European hopefuls Paul Lawrie and Jose Maria Olazabal start their rounds with bogeys to fall to one over par.
1940: Tiger Woods begins his round with a par at the 10th. American Jonathan Byrd grabs a birdie to join the group at level par.
1932: Billy Mayfair becomes the third player to get to even par during the third round after a birdie at the second. But KJ Choi leaves that group after a bogey at the fourth.
1927: Korean Choi birdies the third to move to even par.
1922: A second birdie for South African Tim Clark brings him to one over par on a day when no one, so far, seems capable of taming the course.
1913: Ernie Els, who played himself back into contention during the second round, pars the first three holes to stay at one over.
1900: Furyk birdies the third to get to level par for the tournament, while Sergio Garcia picks up a shot to move back to four over.
1845: Garcia, also starting his round at the 10th, suffers back-to-back bogeys to fall to five over for the tournament.
1840: It is a miserable start for American Pat Perez, who scores a quadruple-bogey at the 10th, the first hole of his round.
1830: A bad start for Nick Faldo, who bogeys the first two holes of his round to fall to five over par. His playing partner Mark O'Meara has picked up a shot to get to two over.
1800: The first pairing of Jeff Sluman and Craig Parry complete the opening hole, both dropping a shot.