Bubba Watson shot a 6-under 64. Phil Mickelson and Kenny Perry each carded 66.
Tiger Woods hits from the fairway, near a cart path, on Firestone's second hole. AKRON, Ohio -- Stow native Ben Curtis is tied for 17th place in Thursday's first round of the World Golf Championships-Bridgestone Invitational.
Curtis started hot at Firestone Country Club, recording back-to-back birdies on the par-5, 526-yard second and par-4, 442-yard third holes.
He went on to card two bogeys en route to finishing the front side at even-par 35. His bogeys came on the par-4, 471-yard fourth hole and the par-3, 219-yard seventh hole.
Curtis started the back side with a birdie on the par-4, 410-yard 10th hole but was unable to get a streak going. He made par on each of the remaining eight holes to finish at 1-under 69.
Tiger Woods is 4-over after 13 holes, not off to the start he wanted in quest of his eighth WGC-Bridgestone Invitational title.
Woods, after his first win of the season, has had bogeys on holes No. 1, 2, 5, 9 and 11. His lone birdie was on No. 6.
Perennial majors contender Lee Westwood of England, considered one of the tournament favorites, is 1-over through his first 13 holes.
Phil Mickelson closed his first round on Firestone Country Club's South Course with birdies on six of his last 12 holes to finish with a 4-under par 66.
Bubba Watson, like Mickelson a left-handed golfer, fired a 64 and holds a two-stroke lead over Mickelson and Kenny Perry, who carded a 66. Also at 4-under are Bo Van Pelt and Australia's Adam Scott. Both have played 12 holes.
Masters champion Mickelson has a chance this week to surpass Woods and achieve the world's No. 1 ranking for the first time in his career. Lefty began play on Firestone's back nine, and was 2-over after bogeys on Nos. 14 and 15.
Mickelson birdied the 667-yard, par-5 16th hole. Then, on his back nine, he strung together birdies on hole Nos. 2, 3, 6, 7 and 9.
Watson set up his sterling round with birdies on the 11th through 14th holes.
Chad Campbell and Sean O'Hair shot 3-under 67s. Rickie Fowler, after 12 holes, and South Africa's Reteif Goosen, through eight, are 3-under.
Steve Stricker, Gregory Bourdy of France and Rory McIlroy of Ireland completed their rounds at 2-under, 68. In the clubhouse at 1-under par 69 are Ernie Els of South Africa, Alexander Noren of Sweden and Matt Kuchar.
British Open champion Louis Oosthuizen of South Africa shot a 2-over 72, and U.S. Open champion Graeme McDowell is 1-under through eight holes.