Rickie Fowler was the first big name to make a significant move as birdies flowed for many of the early starters on day one of the U.S. Open.
In the lead-up to the year's second major, much had been made of the daunting challenge posed by Erin Hills, a lengthy Wisconsin venue hosting the tournament for the first time.
However, Fowler birdied three of his first five holes after starting on the 10th and there were plenty of other players making positive initial progress.
Fowler - who tied for second in the 2014 U.S. Open - was soon joined at three under by Brian Harman, while Kim Meen-whee, Charley Hoffman and Brooks Koepka were among several players one shot off the lead.
Playing alongside Fowler, Hideki Matsuyama holed his approach to the par-four 15th for an eagle to move into red figures.
Yet the third member of that high-profile group, Jon Rahm, made a woeful start, bogeying the 10th, 11th and 14th to dampen the high expectations that had surrounded him coming into the event.
Jordan Spieth and Dustin Johnson each began solidly in the company of another former champion, Martin Kaymer. Spieth was one under after draining a birdie putt from around 20 feet on the 11th and last year's winner Johnson parred his first four holes.
Earlier, Phil Mickelson's withdrawal from the tournament due to the event clashing with his daughter's graduation was confirmed.
The likes of Rory McIlroy, Masters champion Sergio Garcia and Jason Day were among the later starters on Thursday.