Byeong Hun An carded another 6-under 66 to open up a two-stroke lead as the second round of the Sanderson Farms Championship was suspended.
The South Korean continued his fine start at the Country Club of Jackson on Friday, moving to 12 under after his second straight 66.
An started his round with four consecutive birdies before finding water to bogey the par-5 fifth.
The 28-year-old recovered with back-to-back birdies at eight and nine before picking up another shot at the 17th.
An holds a two-shot lead over J.T. Poston (70), George McNeill (67), Scottie Scheffler (66) and Tom Hoge (70).
Hoge and Scheffler are coming off strong showings at the Greenbrier Classic, where they finished second and tied for seventh respectively.
Inclement weather led to a delay on the opening day and darkness meant 57 players were unable to finish their second rounds.
Cameron Percy is the best-placed of those yet to get through 36 holes, sitting at 9 under through 11 and in outright sixth.
Carlos Ortiz (71) and Harris English (71) are tied for seventh at 8 under, alongside Seamus Power, who is through 11.
Joaquin Niemann, the 20-year-old Chilean who won the Greenbrier Classic, is back at 4 under through 16 holes in his second round.