Canada's Mackenzie Hughes carded a nine-under 63 to take a one-shot lead from a tight field after the first round of the Procore Championship in Napa, California.
Hughes built on a stellar front nine, which featured six birdies, with five more after the turn.
The only downside of his day was a pair of bogeys on the 14th and 15th holes, which helped keep the American pair of Ben Griffin and Matt McCarty within touching distance.
Just four shots separate the top nine players, with amateur Jackson Koivun among those in the hunt headed into the second round.
World number one Scottie Scheffler’s streak of 21 sub-70 scores was broken as he finished his round on two under.
Scheffler’s record had tied Patrick Cantlay for the longest streak in the modern era.
Seamus Power is currently just inside the cut line and sits eight shots off the lead following an opening-round
