Jordan Spieth turned in 32 to move within just one shot of the lead as the second round of the US PGA Championship got under way at a wet Baltusrol Golf Club.
Torrential rain overnight had soaked the New Jersey layout and a further downpour in the morning resulted in 40 minutes of play being lost due to the course being flooded.
Spieth was about to hit his first shot of the day off the tenth tee when play was halted but the delay did not distract him as the American birdied his first two holes before dropping a shot on the 12th.
He picked it back up on the 13th, though, and when the World Number Three took advantage of the par five 17th and 18th, he was four under and just one behind Jimmy Walker, who was among the afternoon starters.
England's Ross Fisher and Argentinian Emiliano Grillo were also among the later starters at four under, with the group a further shot back growing as players took advantage of the softer conditions.
Patrick Reed had birdies on the 11th, 14th and 15th to sit at three under after eight holes, alongside Webb Simpson who was two under for his first seven.
Andrew Johnston was in the group at two under after taking advantage of the two par fives with Louis Oosthuizen staying at that mark through his first seven holes.
Martin Kaymer, the 2010 champion, was also in that group but he was two over for the day after 11 holes, a shot clear of Open Championship winner Henrik Stenson, who had dropped two shots in his first eight.
Kiradech Aphibarnrat, Russell Knox, Marc Leishman and Alex Noren were also at one under playing their back nines.
