|Masters 2015 leaderboard|
|-8 J Spieth (US); -5 E Els (SA) C Hoffman (US) J Rose (Eng) J Day (Aus); -4 S Garcia (Spa) R Henley (US)|
|Selected others: -2 P Mickelson (US); -1 R McIlroy (NI); +1 T Woods (US)|
|Click here for full leaderboard|
World number one Rory McIlroy is seven shots behind leader Jordan Spieth after the opening round of the 79th Masters at Augusta.
The Northern Irishman, 25, is aiming to become only the sixth man to win all four majors and made a solid start to the tournament with a battling one-under-par 71.
However, American Spieth, who finished joint runner up to Bubba Watson at last year's Masters, produced the performance of the day, carding nine birdies to open a three-shot lead with an eight-under 64.
England's Justin Rose made an impressive start as he continues his quest for a first Masters title, carding a 67 to sit in a group of four players on five under while former world number one Tiger Woods is nine shots off the pace after a one-over 73.
Spieth versus McIlroy
Spieth, 21, is yet to win a major but arrived in Georgia in fine form, with a win and two runners-up places in his last three PGA Tour events.
He became the first man since Woods in 2011 to record nine birdies in a round, with six arriving in seven holes around the turn.
Spieth's fine display means McIlroy, looking to win his third major in succession, will be determined to get himself firmly in contention with an improved performance in Friday's second round.
He opened with a huge 324-yard drive down the first on a scorching Thursday morning but found the water hazard on the par-five second, scrambling superbly for par with a beautiful back-spinning chip to within four feet.
Having dropped a shot on the par-three sixth he then hit straight back with a fine approach on the seventh for his first birdie of the tournament, but another bogey on the testing par-four 11th slowed his momentum.
A birdie on the par-five 13th was followed by a wonderful 21-foot birdie putt on the 15th, and he was a little unlucky that his tee-shot on the par-three 16th failed to release down the slope of the green.
Rose blossoms, but stays wary
Rose made a strong start to the tournament as he had six birdies and just one bogey to take a share of the clubhouse lead midway through the day, before Spieth made his move in the afternoon.
The 34-year-old, alongside American Charley Hoffman, South African Ernie Els and Australian Jason Day on five under, is well placed to mount a challenge on Friday.
However, having led after the opening round on three previous occasions but still without a Masters title, Rose is keeping his expectations in check.
"There's really no point in getting ahead of yourself," said Rose, who won the 2013 US Open. "So much can happen around this golf course."
"One thing I've learned on this golf course is that if you do make a bogey or two, when you start to chase around here to make up for it, it's not always the best decision."
Work to do for Woods
Much of the pre-tournament focus had been on Woods, who was playing in just his third tournament of the year and his first after taking an indefinite break from golf. two months ago.
Having shot an 82 in his first tournament of 2015 and then withdrawing after 11 holes in the second, there was plenty of uncertainty about how the 39-year-old would get on at the Masters.
Woods has not won a major since the 2008 US Open and he made a disappointing start on Thursday, bogeying the par-four first, but recovered with a birdie on the second.
He added two further birdies but three bogeys meant he signed for a one over 73 and he immediately headed off to the practice area.
Casey in contention
Paul Casey, making his first Masters appearance since 2012, is in contention for a maiden Major title after finishing with a three-under-par 69.
A bogey on the 18th cost him a place higher up the leaderboard, but the Englishman was satisfied with his round.
"It is great to be back," Casey said. "This is a golf course I play well and I love to play it."
Casey's compatriot Danny Willett marked his Masters debut with an impressive eagle on his way to a 71.
The 27-year-old holed a 60-foot putt on the 13th and said: "It's the kind of thing you dream of when you're a kid, boxing a long one across the green."
Also finishing the opening round with a 71 was Scotland's Stephen Gallacher, who carded three birdies alongside two bogeys, and Northern Ireland's Graeme McDowell.
English duo Ian Poulter and Lee Westwood both finished on 73, one over, while Scot Sandy Lyle is two over.
Welshman Jamie Donaldson, partnering Tiger Woods and Jimmy Walker, finished with a two-over 74, with compatriot Ian Woosnam a shot further back.