Australian Jason Day, runner-up in both The Masters Tournament and US Open Championship this season, posted a superb seven under par 63 at the World Golf Championships-Bridgestone Invitational in Akron.
Day outscored playing partner Phil Mickelson and England's World Number Two Lee Westwood by four in establishing an early three stroke lead over a group which included 2009 Open Champion Stewart Cink and Dane Thomas Björn.
Rory McIlroy, in his first start in America since capturing the US Open by eight shots in June, and World Number One Luke Donald both returned 68s, while last year's US Open Champion Graeme McDowell went to the turn in 32, but then stumbled home in 39 for a one over 71.
Tiger Woods, winner of the title seven times in nine attempts before finishing joint 78th out of 80 last year, had not played since May 12 because of knee and Achilles tendon injuries.
His opening drive was pushed into a fairway bunker, but from there he found the green and two-putted from almost 30 feet for a par.
Woods was paired with Open Champion Darren Clarke. The 42 year old Northern Irishman was in the same sand trap off the tee, but could do no better than a bogey five.
Day, not 24 until November, was off and running with a birdie on the tenth and picked up strokes at the 13th, 16th and 18th to turn in 31.
Further birdies came on the long second and fifth before he finished his day's work in style with an 18 foot putt that stretched his advantage still further.
McIlroy bogeyed two of his first four holes, but sank a 12 foot birdie putt on the 17th - his eighth - and then burst into life on the outward half.
A 230 yard second shot to within six feet of the flag set up an eagle on the 526 yard second and he followed that with a birdie before parring his way in.
In contrast, McDowell turned in 32, but ran up sixes at the second and 442 yard third after poor drives.
The Ulsterman was partnering Westwood, who turned in a level par 35 before grabbing birdies at the first, second, fifth and sixth.
Donald kept a bogey off his card, but had to settle for only two birdies at the tenth and second.
Woods was also in sand beside the second fairway. Where McIlroy had eagled the former World Number One, now 28th on the Official World Golf Ranking, had to settle for par.
He then holed from nearly 18 feet at the next, but that was for par as well after going over the green.
The big move of the afternoon was being made by Korean Kim Kyung-tae.
Five birdies in his first 11 holes took him second on his own two behind Day, who said: "It felt like it was a boring kind of a game - down the middle, on the green and every two or three holes a birdie.
"I haven't been hitting it as good over the last couple months, but I hit it great today and I'm feeling really good about my game right now.
"I really enjoy playing against the best golfers in the world on the biggest stage. I've always wanted to play on the big stage and I'm finally here.
"Obviously I just want to keep the year going in the right direction. I don't want to go backwards."
McIlroy commented: "It was a decent opening round. I've still got a little bit to work on, but 68 is not a bad start."
Westwood has started working with Dave Stockton on his putting and Bob Rotella on his mind and commented: "I'm not spending so much time over the ball.
"I feel like it freed my stroke a little bit. I catch myself a few times where I had to stand off it because I had taken too long over it.
"I got it right most of the time, it's just a case of practising it.
"A 67 is never anything to complain about around this golf course, even when there's not much wind and it's playing soft. I was pleased with the way I played."
Donald stated: "I could have gone a little bit lower if I had got the putter rolling a little bit better, but tee to green it was very solid.
"Hopefully I can see the lines a bit better tomorrow and make a few more putts."
