Sebastian Cappelen has carded a 65 to lead the Sanderson Farms Championship after the first round in Missouri.
The Danish golfer got off to a perfect start, birdieing the opening three holes at the Country Club of Jackson and picked up further shots at the fifth and seventh holes to reach the turn in 31.
Cappelen dropped his only stroke at the 10th, but then sunk birdies at 11, 13 and 15 to finish the first day on seven-under-par, to lead by two from Robert Streb, Scott Pinckney and Canada's Nick Taylor.
Ireland's Padraig Harrington had threatened to get among the leaders when he climbed to four-under after 11 holes.
However, consecutive bogeys at the 13th and 14th saw the former Open champion end the day with a round of 70.