Hideki Matsuyama had a horror start to his first tournament in more than three months, ending his Thursday round at the RBC Heritage in a tie for 134th position.
England's Ian Poulter and American Mark Hubbard share the lead at 7-under-par after they carded 64s in the PGA Tour's second tournament back from its coronavirus pandemic-necessitated break.
Matsuyama is 10 shots off the pace, his up-and-down round of 74 including three birdies, four bogeys and a double-bogey at the harbor Town Golf Links in South Carolina.
"I didn't have any challenges emotionally, but I couldn't swing or putt the way I wanted to. I need to concentrate more," he said.
The 28-year-old is playing in his first event since the Players Championship in March, which was called off due to virus concerns with the Japanese holding a two-stroke lead having equaled a course record in the first round.
He returned to train in Japan after the tournament cancelation and then to his home in Florida at the end of May.
American Webb Simpson and six others are tied for third, a stroke off the lead, while world No. 1 Rory McIlroy is in 101st and in danger of missing the cut.
The RBC Heritage is being played behind closed doors to prevent the spread of the coronavirus. The players and caddies were tested upon arrival and are asked to fill in questionnaires and undergo temperature tests daily, according to the tournament website.
Last week, Daniel Berger of the United States won the Charles Schwab Challenge, the first PGA Tour event following the suspension.