Gary Woodland led the way in the opening stages of the US PGA Championship but Thorbjørn Olesen was one of four just a shot off the lead at Quail Hollow Club.
Woodland turned in 32 to get to three under with Dane Olesen alongside England's Paul Casey and American duo Tony Finau and Jim Herman.
There was then a group of 11 players at one under including last week's winner Hideki Matsuyama and English pair Chris Wood and Lee Westwood.
American Woodland made birdies on the second, sixth and seventh to jump into the lead but he could not shake off a strong chasing pack on the opening morning.
Olesen had put an approach to seven feet to birdie the second and while he dropped a shot on the sixth, back-to-back gains on the seventh and eighth had him in the group one back.
Casey had been three under after five holes after starting on the tenth but bogeyed the 17th to turn in 34, while Herman had two birdies in ten holes and Finau three in 12.
Matsuyama - who won the WGC-Bridgestone Invitational with a stunning closing 61 last week - started birdie-birdie from the tenth and while he made another gain on the 15th, he gave shots back on the 12th and 18th.
Wood also had three birdies and two bogeys as he played the back nine in 35 blows, while Westwood had a single birdie on the 14th in his first five holes.
South African Dylan Frittelli, a European Tour winner this season, had two birdies and a bogey in his first 11 holes.
Swede David Lingmerth, South Korea's Sunghoon Kang and Americans Scott Brown, Zach Johnson, Keegan Bradley, Xander Schauffele and Grayson Murray were also one under.
In the group of 2017 Major champions, Brooks Koepka and Jordan Speith were level par and Sergio Garcia was two over after eight holes.
There was then a group of 11 players at one under including last week's winner Hideki Matsuyama and English pair Chris Wood and Lee Westwood.
American Woodland made birdies on the second, sixth and seventh to jump into the lead but he could not shake off a strong chasing pack on the opening morning.
Olesen had put an approach to seven feet to birdie the second and while he dropped a shot on the sixth, back-to-back gains on the seventh and eighth had him in the group one back.
Casey had been three under after five holes after starting on the tenth but bogeyed the 17th to turn in 34, while Herman had two birdies in ten holes and Finau three in 12.
Matsuyama - who won the WGC-Bridgestone Invitational with a stunning closing 61 last week - started birdie-birdie from the tenth and while he made another gain on the 15th, he gave shots back on the 12th and 18th.
Wood also had three birdies and two bogeys as he played the back nine in 35 blows, while Westwood had a single birdie on the 14th in his first five holes.
South African Dylan Frittelli, a European Tour winner this season, had two birdies and a bogey in his first 11 holes.
Swede David Lingmerth, South Korea's Sunghoon Kang and Americans Scott Brown, Zach Johnson, Keegan Bradley, Xander Schauffele and Grayson Murray were also one under.
In the group of 2017 Major champions, Brooks Koepka and Jordan Speith were level par and Sergio Garcia was two over after eight holes.
