Woods falls seven behind

Pennsylvania - Tiger Woods drove like the world number one then putted like a 12-handicapper as he slipped seven strokes off the pace after the first round of the AT&T National in testing conditions on Thursday.

Woods, who was unerringly accurate off the tee, missed several easy putts as he shot a three-over 73, seven shots behind joint leaders Australian Jason Day, India's Arjun Atwal and Americans Nick Watney and Joe Ogilvie.

"I just putted awful," the world number one told reporters after he dropped four shots in an error-strewn four-hole stretch on the back nine. "It was a frustrating day on the greens, especially how good I was driving it.

"My speed was good but I never hit the ball on line. Even when I hit my putts on the exact line I wanted, they still didn't go in."

A three-putt bogey at the par-three 14th set the tone for his poor finish, and he dropped another shot at the par-five 16th after a woeful wedge shot found a greenside trap.

Worse followed at the par-three 17th, where his six-iron found the pond in front of the green, leading to a double bogey before he squandered a five-foot birdie chance at the last when his ball lipped-out. Woods, who had to contend with a fluctuating breeze after all of the leaders enjoyed the benign morning conditions, tried to take solace from his driving.

"If I keep hitting it like this, I'll be fine," he said. "It felt good to drive it on a string again.

"I hit what I thought were two bad drives and both of them landed in the fairway and just ran into the rough."

Joint leader Day, who posted his maiden PGA Tour win in May at the Byron Nelson Championship, was pleased with his four-under 66 as he has just returned after three weeks off recovering from a chronic sinus infection that might require surgery.

"I only had one three-putt and that was the only bogey of the day. Overall, I hit the ball really well," Day said.

Atwal, who is playing this week because he received an invitation at the request of Woods, his Florida neighbour and frequent practice round companion.

"I didn't really know what to expect because I hit it really bad last week in Hartford," said Atwal, who is playing on a medical extension this year after missing four months last year with an injured shoulder.

"You never know until you tee it up what to expect but it was a bit of a surprise."