Brooks Koepka made a hot start in his bid for a third straight U.S. Open title, while Tiger Woods was forced to battle in the early stages.
Koepka, bidding to become the first man since Willie Anderson in the early 1900s to win the major three consecutive times, was in impressive form in his opening round at Pebble Beach on Thursday.
The four-time major champion made 12 and 11-footers for birdies on the first and third holes before chipping in at the fifth to get to three under.
Koepka almost took full advantage of the par-five sixth, making another birdie after an eagle putt just missed, to move into four under.
He is just a stroke behind clubhouse leaders Rickie Fowler, Xander Schauffele and Louis Oosthuizen, who fired first-round 66s.
Norwegian amateur Viktor Hovland joined Koepka on four under through six holes to be tied for fourth.
After seeing a 24-footer for birdie stop just short, Woods – a three-time U.S. Open champion – salvaged pars on the second and third holes before a birdie at the fourth.
However, Woods dropped back to one over after a poor tee shot led to a double bogey at the par-three fifth.
Last year's Open champion Francesco Molinari (two under through six) and Jordan Spieth (one under through four) made decent starts.