An early start proved to be key for Daniel Summerhays as he took a three-shot lead at the Sanderson Farms Championship in Mississippi.
Summerhays finished with a blemish-free nine-under-par 63 to head the leaderboard - although half of the field are yet to complete the opening round due to the weather.
Play was halted at around 2pm local time by thunderstorms - and although numerous attempts were made to restart, the course was deemed too soggy to resume.
By that time Summerhays was already safely back in the clubhouse having holed seven birdies and an eagle to move three shots clear of fellow Americans Will Claxton, Michael Bradley and Jonathan Randolph.
"I definitely got things going with that eagle on 18," Summerhays told pgatour.com. "That was nice."
The round continued Summerhays' good form from last week's John Deere Classic, where he narrowly missed out on a play-off after bogeying his final hole.
"You have to enjoy these moments," Summerhays said. "Sometimes we take good golf for granted and you forget how hard this game is sometimes. It can be a really hard game, so I'm just soaking it in.
"I'm really excited about where my game is at and I'm looking forward to getting back into the swing of things on the weekend and testing myself again."
Former champions Chad Campbell and DJ Trahan were both in a group of seven on five under.