Duval, aiming to win the title for the third time, was joined at the top of the leaderboard by Japan's Hidemichi Tanaka who birdied five of the last eight holes in Virginia.

Two shots back are Duval's Ryder Cup team mate Scott Hoch, 1995 US Open champion Corey Pavin, Bart Bryant, Argentina's Jose Coceres and Loren Roberts.

Duval, who was one of the more successful Americans at the Ryder Cup, said his display under pressure at the Belfry had given him confidence.

"It's always easy to shoot good scores when you're playing well and when you have some confidence," Duval said.

"In the atmosphere of the Ryder Cup, hitting it in the fairway the first hole of my first match gave me a little bit of a swagger back."

Duval had one eagle, seven birdies and two bogeys in his first round to record his best score of 2002.

Tanaka admitted to feeling under the weather, despite his awesome round.

"I wasn't feeling very well today," he said.

"However, I took each shot one shot at a time carefully. I felt tee shots were very important, to keep it on the fairway, hit a good tee shot."

Tanaka recorded eight birdies and only one bogey.