Ireland's Paul Dunne carded a one-over par 71 on day one of the US Amateur Championships at Olympia Fields in Illinois.
The 22-year-old fired birdies on the first, sixth and 16th holes, but was undone by bogeys on the fifth, 11th, 14th and 18th.
Dunne, who shot to prominence last month when he held a share of the lead after 54 holes at the 144th Open Championship, sits six shots behind America's Matt NeSmith, the clubhouse leader on five-under.
Waterford's Gary Hurley shot a two-over par 72, as did Cormac Sharvin from Ardglass, while Scotland's Grant Forrest posted 74 with England's Henry Smart three shots further back on 77.
