FIRST ROUND LEADERBOARD (US unless stated):
-6 Fred Couples -5 T Watson, P Mickelson, L Westwood (GB), Y Yang (Kor), KJ Choi -4 T Woods, A Kim, N Watney, I Poulter (GB), R Barnes -3 D Toms, S Lyle (GB), T Immelman (SA), C Schwartzel (SA), A Scott (Aus)
Masters leaderboard (external website)
Tiger's first round highlights
By Rob Hodgetts
BBC Sport at Augusta
Fred Couples rolled back the years to lead the Masters after round one as Tiger Woods put himself in contention despite a four-month absence from the game.
The 50-year-old Couples fired a six-under 66 on a blustery, grey day at Augusta to lead by one from Lee Westwood, Tom Watson, Phil Mickelson, YE Yang and KJ Choi, with Woods lurking just two shots adrift.
Woods's return from time out because of a sex scandal has dominated the tournament in the build-up, and massive crowds gathered for his opening tee shot on Thursday.
But the world number one showed few signs of rust and shot 68 for four under, the first time he has beaten 70 in the first round in 15 Masters tournaments.
Couples is enjoying a new lease of life on the senior tour in America with three wins this season, and he maintained his form with his best-ever round in 25 appearances at Augusta.
"I didn't think I would shoot 66 today," he said. "I think it's by far the best round I have had here. I felt very stiff, the wind was blowing so hard and I felt really tight.
"But I made a lot of putts. We still have to come out tomorrow and play really well on a really hard golf course."
Couples rolled back the years to lead after the first round in Augusta
The 1992 champion, who reached the turn two under and added four more birdies, continued the trend of veterans performing well in recent majors after Greg Norman in the Open two years ago and Watson at Turnberry last year.
The 60-year-old Watson showed his play-off loss to Stewart Cink in last year's Open was not a one-off swansong either as he put himself in contention for a third Masters Green Jacket and ninth major title, 27 years after his last.
Watson, the 1977 and 1981 Masters champion, birdied the first and third and three of the last four holes for his best opening round in his 37 Masters appearances.
"The last four or five years I've gone into the tournament feeling like the course was too big for me, and today, as it was last year, the course was set up where you could get to some of the pins," said Watson.
Westwood, who has yet to win a major title, reached the turn one under and added four further birdies coming home.
The 36-year-old, who has finished third in the last two majors, has a mixed record at Augusta with a best finish of tied sixth in 1999, but he believes his experience in 10 previous Masters is finally paying off.
Tiger's amazing draw shot on 9th
"I was saying to my caddie Billy that although it's the best I've ever played around here, it's the most comfortable I've felt on the golf course," he said.
"I'm gradually working out a way for me to get around this course in as few shots as possible."
Mickelson was one under after 12 but eagled the 510-yard par-five 13th after flying the green with his second shot and draining a 30ft putt. He added birdies at 14 and 15 to get to five under.
"It's a good start," said Mickelson. "My expectations are high. I hit a lot of good drives and a number of good iron shots and putted extremely well.
Watson is aiming for his third Masters victory
"The ones that missed were catching lips, which is a good sign. The greens were receptive which in this wind allowed for a lot of guys to score."
Yang is the man who ended Woods's record of winning all 14 of his major titles when leading going into the final round when he clinched the USPGA title at Hazeltine last August. His victory was the first major title for an Asian-born male.
"Everything came to me very comfortably and I've set my personal record on the course, so it feels really good," said Yang. "Hopefully I can sustain this. I don't want to be too aggressive."
England's Ian Poulter claimed six birdies to join Woods on four under while Sandy Lyle of Scotland, Masters champion in 1988, fired three birdies in his closing four holes for a three-under 69.
Two-time Masters runner-up Ernie Els, who has rediscovered his form with two straight wins in America this season, dropped two shots on the 18th to end one under, the same score as 52-year-old two-time Masters champion Bernhard Langer and 16-year-old Italian amateur Matteo Manassero.
Defending champion Angel Cabrera reached three under after eight but a double-bogey seven on the 13th, the same hole Mickelson eagled, dropped him back and two bogeys in the last three holes gave him a one-over 73.
Ryan Moore chips in on 12th
England's Luke Donald, who tied third on his debut in 2005, signed for a 74 alongside South Africa's Retief Goosen, a two-time US Open winner, Ireland's three-time major winner Padraig Harrington, Spain's Sergio Garcia and Australian Geoff Ogilvy, who won the US Open in 2006.
Harrington had three birdies, three bogeys and a double bogey and admitted afterwards that he "didn't play very well".
"I hit some really poor shots and lost my co-ordination," said the 38-year-old Dubliner. "I was chasing a birdie at the end and then hit another poor tee shot at 18 which gives me a lot of work to do over the next three days."
There was bad news for a host of other players from Great Britain and Northern Ireland.
Paul Casey of England carded 75, as did Northern Ireland's Graeme McDowell, who was the leading European last year in a tie for 17th.
England's Ross Fisher, who was fifth in the US Open last year and led the Open going into the final round before fading to 13th, shot 77, while countryman Oliver Wilson, who went to college in Augusta, carded a six-over 78.
English debutants Simon Dyson and Chris Wood also struggled, ending five over and six over respectively.
Jim Furyk, the 2003 US Open champion and world number five amassed a score of 80, one behind Chad Campbell, who lost out in last year's play-off.
Furyk's card was only one shot better than the 52-year-old Ian Woosnam, the 1991 Masters champion, and three away from the worst total of the 96-man field, carded by 2005 US Open winner Michael Campbell of New Zealand.