AUGUSTA - Adam Scott made a storming start to the Masters on Thursday as he opened his campaign to become the first back-to-back champion at Augusta National since Tiger Woods in 2002. The Australian, who last year became the first player from his country to win the Masters, carded a three-under 69, which could have been even better had he not found water en route to a double-bogey five at the treacherous 12th.It was the best first round by a defending Masters champion since Jose Maria Olazabal shot a 66 in 1995. Scott tucked himself in just one stroke back from Bill Haas, a 31-year-old American ranked 31st in the world who sank a five-footer at the last for the day's best round of 68. Late in the day, Scott was joined on three-under by Louis Oosthuizen and the man who beat the South African in a playoff to win the Masters two years ago, Bubba Watson.Tied for fourth, a further stroke back, was a sextet comprising Americans Kevin Stadler, Gary Woodland, Jimmy Walker and Brandt Snedeker as well as Jonas Blixt of Sweden and K.J. Choi of South Korea. Tournament favorite Rory McIlroy was among a large group of players bunched on 71. Scott opened confidently with a birdie and was four under after 10 holes before he hit into the water at the 12th for the first time in his career. But a birdie at 14 got him back to three-under and he scrambled well to save par at Augusta's tough closing hole. "I feel like I am playing really well," Scott said. "I felt I played good enough to shoot in the 60s today so it was good to make that par save at the last. Very happy the way I played tee to green. I hit the one poor shot at 12 which cost me a couple of shots. Very pleased to get off to such a good start and there is no doubt that winning the Masters last year has made me more comfortable on the first tee than I've ever been in the past because I didn't have the legs jangling for six or seven holes like usual, so that was enjoyable for me today."Haas, whose father Jay placed third in the 1995 Masters, had six birdies against two bogeys en route to his 68, but it was the birdie at the tough 18th that brought him the most satisfaction. He refused, however, to get too far ahead of himself. "I was leading last week (at Houston) after the first round and finished 37th, so I know there's tons of golf left," he said. "And maybe understanding that, I know that I can't expect too much. You've just got to go out there and keep playing golf, try to hit that fairway on number one tomorrow."In the absence though injury of world number one Tiger Woods, it was the group containing 24-year-old Irishman McIlroy and two rising US stars -- 20-year-old Jordan Spieth and 23-year-old Patrick Reed -- that drew the biggest fan following. McIlroy and Spieth shared the honors in that joist, both scoring 71s, while Reed bogeyed the last three holes to settle for a 73. McIlroy said it had been impressed by the composure showed by his younger playing partners on what had been "a good day" for him. "There's a lot of good young guys coming up, coming through, and I feel like I'm one of the older, well not older, but there's maybe Rickie Fowler, Jason Day, myself, these guys, Matteo Manassero, there's a lot of good young players coming up," McIlroy said.There was big trouble early on for Augusta crowd-pleaser Phil Mickelson when he triple-bogeyed the seventh to get to the turn in 39. The three-time former champion bounced back with birdies at 10 and 13, but he sent his approach to the 15th into the water and a double bogey seven brought him in three holes later with a 76 -- equalling his worst Masters start in what is his 22nd appearance dating back to 1991."Disappointing for sure," the five-time major winner said. "But we got a long ways to go and I've got a lot of work to do and I don't feel like my game is off, I really don't." The man he pipped for the first of his titles at Augusta National in 2004, Ernie Els, also struggled to a 75, while Argentinian Angel Cabrera, who lost in a playoff to Scott last year, limped to a six-over 78, the same mark where 2008 champion Zach Johnson ended the day. Jason Dufner, who won the last major played at the PGA Championship last August, fared even worse, taking a nine at the par-five 13th en route to a crippling 80.