The big-hitting Swede, who won the Accenture Match Play Championship earlier this year, shot even-par 72 to get in contention, three strokes off the lead.
'I'm happy with level par because the game doesn't feel 100 percent and the swing is so-so,' said Stenson, who came into the week ranked sixth in the world. 'But I made some good putts and was pretty sharp around the greens, which is why I managed to keep it together as well as that.'
Stenson has been down on his game of late, saying he was hoping simply for a top-10 finish at Augusta this year. He said he flared a couple irons out to the right in his opening round -- a sign that things aren't quite yet worked out.
'It comes with not feeling comfortable over the ball, so I'm going to the range right now and keep working on my game,' he said. 'That's all I can do and hopefully I can feel a little better tomorrow.'
Fred Couples' achy back held up through the round. His pride might be a different matter.
The 1992 champion came to Augusta having played only two competitive rounds this year because of severe back problems. He held up fine through the first nine, coming in with a 37. But the wheels came off on the back nine, and he finished his round in particularly brutal fashion.
After pushing his drive on the par-4 18th into trees off the right side of the fairway, Couples' second shot sailed over the fairway and onto a hill that runs between the 9th and 18th greens.
That wasn't the worst of it.
After several seconds, the ball began rolling slowly down the hill. A security guard chased after it, bellowing at fans to get out of the way. It finally came to a rest at the bottom of the hill.
Couples hit a low shot that landed on the green and drew loud applause from the adoring fans. But a few seconds later, the ball began another slow roll and trickled off the green.
Couples chipped to within 8 feet of the pin, and two-putted from there for a double-bogey that left him at 4-over 76.
PLAYER PLAYS ON
Gary Player would probably be the first to tell people that his mind is sharp as a tack. Funny, then, to see him forget to bring something pretty basic to the course Thursday -- like a ball marker.
The 71-year-old former champion held up play for a brief moment on the first green when he realized he had nothing to mark his ball on the green.
'No big deal,' said Vaughn Taylor, who was playing with the wee South African. 'You just kind of chuckle about it and play on.'
Player was among the older champions that members were targeting a few years ago, when they sent out letters subtly suggesting they consider not taking advantage of one of the tournament's most storied traditions -- lifetime exemptions for all winners.
Player will have none of it, at least not yet. His goal is to play this year and next so he can say he competed in 51 Masters, which would be one more than Arnold Palmer.
As he found out once again Thursday, getting those rounds in is work.
'This place has turned out to be one of the three toughest courses in the world,' said Player, who shot an 83 that included two 7's on the back nine.
The other two on his list: The Links in South Africa and Carnoustie, the home of this year's British Open.
ANATOMY OF A SNOWMAN
There were seven 8s logged on Thursday, none uglier or more ill-timed than Padraig Harrington's on the par-5 15th.
It turned a promising round, albeit one in which he didn't chip or putt very well, into a semi-disaster. He finished at 5-over 77.
Harrington's strategy going into the narrow green surrounded by two small ponds was to avoid hitting long, and risking the ball rolling into the back water.
'I succeeded very nicely,' he said ... but only by sticking in the water in front.
Another ugly 8 was logged by amateur Casey Watabu. He hit his tee shot on No. 12 short and watched it slowly and painfully roll backward into the water. Later came an instant replay, after he skulled his drop short of the green and down the hill, also into the drink.
His fifth went into the sand in back of the green, then he got out and two-putted for the quintuple bogey. It was still five shots short of the famous 13 logged there by Tom Weiskopf in 1980.
RIDE, RYDER, RIDE
The first round of the Masters offered more proof that team play and medal play are two completely different animals.
Of the nine below-par rounds shot on Thursday, four belonged to Americans who were on the team that got blown out in the Ryder Cup in Ireland last fall.
Brett Wetterich was a co-leader at 3-under. Augusta native Vaughn Taylor, Zach Johnson and J.J. Henry all went 1 under. Those four combined to go 1-5-5 last year in America's 18 1/2 -9 1/2 blowout loss.
Meanwhile, two stars from the European victory -- Sergio Garcia and Jose Maria Olazabal -- shot 76 and 74, respectively.
MORE THAN RESPECTABLE
Craig Stadler, the 1982 champion, spent most of the day on the leaderboard. A double-bogey on 16 knocked him off, but he still shot 74 -- ahead of other past champions like Phil Mickelson and only one stroke behind Tiger Woods.
'The golf course gets harder and longer, but I don't get any younger,' said the 53-year-old Stadler.
He wasn't the only veteran to enjoy a good day.
Fuzzy Zoeller also spent much of the day under par and finished with a 74.
At the end, the 1979 champion made a comment sure to go over well with the Augusta brass: 'Washington Road is softer than the No. 1 green,' he said. 'That's the hardest green I think I've ever seen.'
Tom Watson, the 57-year-old two-time champion, finished at 75, and Ben Crenshaw shot 76. With scores not plummeting, all these past champions could have a chance at making the cut.
'Last year, I actually hit it better and shot 77 and 78,' Stadler said. 'It was nice to kind of hang in there.'
Fred Funk had the worst collapse of the day, turning a front-side 36 into an 82. ... Ian Woosnam withdrew with a bad back before teeing off...Former two-time champion Seve Ballersteros, playing for the first time in four years, shot a 14-over 86.
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