Tiger Woods returned to action after back surgery with a disappointing three-over par 74 on the opening day of the Quicken Loans National at Congressional.
The former world number one underwent a microdiscectomy in March and missed the Masters before being cleared to make his comeback in Maryland.
Woods got off to a terrible start, making seven bogeys on his first 12 holes, to sit at the bottom of the leaderboard on six-over par.
He rallied with birdies on the fourth, seventh and eighth holes to sit eight shots behind Australian Greg Chalmers, who leads the way on five under par after the first round.
"I think the hard part was just getting into the rhythm of playing competitively," Woods told the PGA website.
"You play with your buddies all day for cash and stuff but it's just not the same. It's not the same as tournament golf, different level. Adrenaline is rushing and I hit the ball further out here than I do at home.
"It unfortunately took a while to get the feel for it. My feels were off."
Despite the teething issues, the 38-year-old believes he only needs to make minor tweaks to his game to be more competitive over the course of the weekend.
"I made so many little mistakes," Woods added. "So I played a lot better than the score indicated, which is good."
However, the 14-time major champion was most buoyed by the fact that he had no problems at all with his back.
"I had no issues at all," he said. "No twinges, no nothing. It felt fantastic."
Chalmers made light work of the back nine that troubled Woods so much, notching birdies on the 10th, 16th and 17th holes.
A bogey on the second hole looked to have dented his progress, but the 40-year-old scored a hat-trick of birdies on his final holes of the day to seize the initiative.
Last year's winner Bill Haas was two shots behind Chalmers with five holes left of his round and had the Australian firmly within his sights, but he failed to add to his tally of four birdies to card a three-under 68.
He is joined by Erik Compton, Tyrone Van Aswegen and Patrick Reed on two shots behind, while Freddie Jacobson and Ricky Barnes are even closer to Chalmers after registering four under par rounds.