Jacob Bridgeman leads the 3M Open after opening round

Bridgeman, who has missed the cut in his last three starts, covered his final seven holes in five under par to card an opening eight-under-par 63 at TPC Twin Cities.

The world number 206 made a hat-trick of birdies from the 12th, holed out from a bunker for another on the 17th and also birdied the last to edge ahead of Canada's Mackenzie Hughes, who had posted a flawless 64.

Open Championship runner-up Billy Horschel had earlier withdrawn from the penultimate regular event of the PGA Tour season ahead of his first round.

Horschel, who birdied the last three holes in the final round at Royal Troon on Sunday to share second place with Justin Rose, cited illness in quotes given to tournament officials.

"Yeah, it was unfortunate," the world number 33 said. "I wasn't feeling great late last night and took some medicine.

"Had decent sleep but woke up and just have a fever, body is just not wanting to respond, every muscle feels like it's locked up. Tried to do a little warm-up in the gym, just didn't respond.

"Tried to go out to the golf course and hit some balls, body's just not wanting to cooperate.

"(It's) disappointing. I was looking forward to playing here at 3M. Played here last year, had a good finish. The event is well run so very disappointed not to be able to play here after coming off a really great finish last week."

Horschel was replaced in the field by first reserve Adam Long.