Andrew Landry was the unlikely leader of the U.S. Open when play was suspended on Thursday after just over three hours of action.
World number 624 Landry, who came through local and sectional qualifiers to earn his place at Oakmont, reached three under through 11 holes of his opening round before dangerous weather conditions and an approaching storm forced organisers to call players off the course at 10:04am local time (3:04pm BST).
A somewhat more familiar quartet - Lee Westwood, Danny Lee, Matt Fitzpatrick and Kevin Streelman were all two under and shared second.
Reigning champion Jordan Spieth, meanwhile, had enjoyed a solid start to his title defence, mixing three pars with a birdie after starting on the 10th.
Ten players were in red numbers early on, with rain having softened a course that is expected to provide a fearsome test as the week goes on.
Despite birdies initially proving more gettable than many had anticipated, Rory McIlroy bogeyed two of the first three holes before clawing back some ground with a gain at the fourth.
A large chunk of the field had yet to tee off in the year's second major, with world number one Jason Day among the wave of afternoon starters.