Dahmen set the mark early thanks to a solid performance tee to green. Straka, a 25-year-old from Vienna, Austria, joined Dahmen on top after turning in a bogey-free performance where he led the field in strokes gained: putting.
Former world No. 1 Luke Donald, who is making his second start this season after missing nearly a year due to a back injury, sits in a tie for third after shooting a first-round 67.
The shot of the day belonged to Knox, who made an albatross on the par-5 11th. The replay shows what golf coverage would look like without any camera operators.