Luke Donald was facing a battle to hold on to his World Number One status after an ordinary opening round in the RBC Heritage in South Carolina.
Donald needs to finish in the top eight at Harbour Town - where he lost a play-off to Brandt Snedeker last year - to remain ahead of Ryder Cup team-mate Rory McIlroy in the Official World Golf Ranking.
But the Englishman, who would have definitely lost his position had he not played this week, struggled to a four over par 75 to lie eight shots off first round leaders Chad Campbell, Vaughn Taylor and Colt Knost.
Starting from the tenth, Donald dropped shots at the 12th and 15th to reach the turn in 37.
He then recovered from a bogey on the first with a birdie on the par five second, but ran up a double-bogey six on the sixth to continue the disappointing form shown in last week's Masters Tournament.
It was a different story for Campbell, who raced to four under through seven holes but could make no further inroads with a pair of bogeys cancelling out two further birdies.
Taylor and Knost, meanwhile, made an impact at the end of their rounds.
Having started at the tenth, Taylor holed from 103 yards to eagle his last hole, the ninth, while Knost, one of the last to finish, birdied two of his final three holes.
Jim Furyk headed a group of four players on three under, while Sweden’s Carl Pettersson was the leading European challenger after a one under par 70, one better than defending champion Snedeker.
