Rickie Fowler reached the turn in 33 to take a share of the early lead as the US PGA Championship got under way at Baltusrol Golf Club.
The Abu Dhabi HSBC Golf Championship winner finished in the top five of all four Major Championships in 2014 but since then has not registered a top ten in golf's big four events with three missed cuts.
That win on the Desert Swing was his second on the European Tour in as many seasons, however, and the World Number Seven made a fine start in his quest for a third.
The American recovered from a bogey on the tenth, his first, with birdies on the 11th, 13th, 14th and 18th to join countrymen Harris English and Jimmy Walker at the summit on three under.
English also turned in 33 from the tenth with gains at the 11th, 14th and 18th, while Walker had birdies on the 13th, 15th and 16th in his first eight holes.
American Brian Stuard and Argentina's Emiliano Grillo were then a shot further back after ten holes, with England's Paul Casey at the same mark having played eight.
BMW PGA Championship winner Chris Wood, Turkish Airlines Open champion Victor Dubuisson, Maybank Championship Malaysia winner Marcus Fraser and Spaniard Rafa Cabrera Bello were then all in the group at one under around the turn, alongside World Number One and defending champion Jason Day.
Two-time champion and World Number Four Rory McIlroy was playing alongside Day and he was two over after six holes.
