Ian Poulter admitted he is as shocked as anyone to find himself in contention heading into Friday's second round at the World Golf Championships-Bridgestone Invitational in Ohio.

Poulter bounced back from missing the cut at last month's Open Championship at Turnberry with an opening three-under-par 67 at Firestone Country Club, three shots behind overnight leader Padraig Harrington in a tie for fifth place.

The English Ryder Cup player's four-birdie, one-bogey 67 last night, his one dropped shot coming at the par-three 15th hole, was also unexpected given his unusual approach to this tournament.

"Very surprising start, really," Poulter said. "Obviously Turnberry wasn't quite what I wanted - played terrible, and took a week off straight afterward, which was really nice to get away from golf for a week.

"Started to play a little bit last week, things were feeling okay, and then I got here, and posture, stance, ball position, grip... the whole thing felt awful.

"I've been working hard on the range the last couple of days to try to get it right.

"I got up extra early this morning, did some extra practice which I don't normally do before tournament day with a camera, and I started to feel a bit better.

"Four under par through 11 holes was very nice."

Poulter was particularly pleased with his play on the greens, needing just 24 putts in his round.

"Yeah, I putted lovely," he said. "Again, not doing an awful lot of putting practice over the last few weeks, knowing that coming into this golf tournament the greens were always really fast.

"I did a bit of practice Tuesday, Wednesday, and I started to roll the ball real nice. You need to do that if your golf game doesn't feel quite there.

"And then obviously I started to hit a couple of good golf shots and then obviously rolling a couple putts in from 30, 40 feet, which always helps."

Also helpful, said Poulter, was starting a tournament without feeling any pressure.

"I think you can certainly have too much expectation going into a lot of big golf tournaments, and as we know, it can bite you pretty quickly," he said.

"To be able to go out there, no expectations apart from really trying to swing the golf club well and trying to make decent golf swings, you find yourself on top of the leaderboard. So pretty happy."