• Defending champion Scottie Scheffler is well placed after a four-under 68, while Tiger Woods limped to a 74.
• Stormy weather is forecast for the next two days, raising prospects of a first Monday finish since 1983.
Jon Rahm, Viktor Hovland and Brooks Koepka shot superb seven-under-par 65s to lead the Masters after day one as Rory McIlroy made another slow start.
The 33-year-old Northern Irishman holed five birdies but they were cancelled out as he carded a level-par 72.
Defending championScottie Scheffler is well placed after a four-under 68, while Tiger Woods limped to a 74.
Stormy weather is forecast for the next two days, raising prospects of a first Monday finish since 1983.
The predicted incoming rain at Augusta has led to Masters organisers bringing Friday's tee-times forward by 30 minutes. The second round will now start at 12:30 BST.
However, the calm conditions on Thursday enabled 16 players to shoot under 70 on a scoreable opening day.
Australian former world number one Jason Day and American Cameron Young are the closest to the three co-leaders after they shot a five-under 67.
Ireland's 2019 Open champion Shane Lowry, American world number seven Xander Schauffele and Australia's 2013 Masters winnerAdam Scott are alongside Scheffler, three shots back on a star-studded leaderboard.
American 23-year-old Sam Bennett is also among that group after recording the first bogey-free round by an amateur in 30 years.
Woods, the 15-time major champion, was playing alongside Hovland and Schauffele but could not match their exploits.
The 47-year-old, who won the last of his five Green Jackets in 2019, has said he will never fully recover from the serious car accident where he nearly lost his leg in February 2021 and his physical condition looked awkward on the steep hills of Augusta National.
He looked in pain several times, none more so than when he played his second shot on the 18th. He had his right foot in a fairway bunker and ended up stumbling backwards into the sand after hitting his ball, hopping on his left leg in obvious discomfort.
Stars jostle for position on thrilling opening day
One of the most exciting weeks in the golfing calendar sees the world's finest men's players making their annual pilgrimage to one of sport's most iconic venues.
With birdies galore, star names jostling on the leaderboard and a host of intriguing storylines, the opening day of the 87th edition of the Masters certainly delivered.
Spanish world number three Rahm produced the most eye-catching round after recovering from a four-putt double bogey on the first hole.
Once known to lose his temper on the course, the 28-year-old Spaniard showed his increasingly mellower side to quickly forget the shocking start.
Instant back-to-back birdies set the tone for an imperious round, knocking in five more birdies and an eagle as he dominated the course with long driving and accurate approaches.
"We forget about the opening green and it was about as comfortable as I've felt this year," said Rahm, whose only major win came at the 2021 US Open.
Norway's Hovland has long been tipped to win one of the prestigious major titles and, having finished as the lowest scoring amateur at Augusta in 2019, the 25-year-old again demonstrated his ability.
One of the best ball-strikers in the men's game, the world number nine moved into an early share of the lead with an eagle at the par-five second.
The perfect start laid the platform for a classy and consistent round, five more birdies by the 13th hole seemingly putting him on course for a commanding lead.
"I hit the ball really well on the front nine but on the back nine I managed to lean on my short game and that's what it is about in a major championship," said Hovland.
"It's not rocket science, you have to hit the shots and if you don't execute it will punish you."
Hovland and Rahm were among the earlier starters, with Koepka - one of 18 players from the breakaway LIV Tour - later joining them at the top of the leaderboard.
How the players from the controversial Saudi-backed project will fare at the Masters is another fascinating element.
Playing 54-hole events and less frequently than their PGA Tour counterparts, many wondered how ready LIV's major champions like Koepka, Open champion Cameron Smith and 2020 Masters victor Dustin Johnson would be to compete.
Four-time major winner Koepka, who won the latest LIV event in Florida last week, answered that emphatically and earned a share of the lead with his eighth birdie of the day on the 18th.
Asked if being a LIV golfer provided extra incentive to succeed, he said: "No. This is Masters week, one of four big ones of the year."
Mcllory adrift after 'scrambling all day'
A major talking point coming into the tournament was McIlroy's latest attempt to be sized up for the Green Jacket.
The world number two was considered as the favourite alongside Scheffler and Rahm but, like on several previous occasions, he already finds himself playing catch-up.
McIlroy birdied the par-five second but that was instantly wiped out with a poor bogey on the par-four third, despite driving to within a few yards of the green.
Worse was to come with a double bogey on the seventh, with McIlroy remaining over par in a rollercoaster round until he rescued some hope with birdies on 15 and 16.
However, a wayward drive on the 17th led to another bogey but an eight-foot par putt on the last at least ensured he starts level on Friday.
"It felt like a bit of a scramble all day. I missed a couple of tee shots left, paid the price and was untidy in some other areas," four-time major winner McIlroy told Sky Sports.
"I tried to stay patient even though there are three guys at seven under and you feel a long way behind them. But there are still 54 holes left, a lot an happen and the weather is coming in."
What else happened on day one?
Scottish veteran Sandy Lyle, the first British player to win the Masters in 1988, accidentally snapped a club on the first hole as he shot a nine-over 81 in what was the penultimate round of his professional career.
The 65-year-old former Ryder Cup player, who recently announced his impending retirement, is finishing his career at the scene of one of his greatest triumphs.
Lyle, who broke his club on a tree branch while escaping from the undergrowth, described his performance as "substandard".
Former world number one Justin Rose, who qualified for a 13th straight Masters by winning at Pebble Beach in February, leads the English contingent after a three-under 69.
US Open champion Mather Fitzpatrick and Tyrrell Hatton - at two under and one under respectively - were the only other Englishmen to finish under par, while Northern Irish amateur Mathew McClean ended up five over despite being the early leader on two under after four holes.
Fred Couples, the 63-year-old American who won the Masters in 1992, became the oldest player to break par at Augusta since Tom Watson in 2015 with a one-under 71.
Four birdies between the 12th and 17th holes moved Couples into joint third position before a bogey on the last - plus the later starters - dropped him down the leaderboard.
An initial field of 88 players at the opening men's major of the year was reduced after American pair Will Zalatoris and Kevin Na withdrew. Zalatoris pulled out minutes before he was scheduled to tee off, while Na was four over after nine when he walked off citing illness.