Ben Crane finished a frustrating day one of the St Jude Classic on top of the leaderboard following storms in Memphis thanks to a bogey-free round of 63.
The American managed to record two birdies in his final two holes, with the second from 27 feet sending him into a two-shot lead on seven-under-par.
Storms delayed the start of play, while darkness intervened in the evening to prevent a number of players from finishing their round on Thursday.
Crane's closest challenger is Peter Malnati, who carded a 65, but his place in second was under threat from Billy Horschel, who also made it to five-under before being forced to abandon his round.
Retief Goosen is one of a number of players just one shot further back, while Phil Mickelson continued his preparations for next week's US Open with a round of three-under.