Ryan Armour's six birdies included a burst of four straight on Friday as he seized a one-shot lead at the weather-hit Sanderson Farms Championship.
Armour, 41 and seeking his first US PGA Tour win, carded a four-under par 68 at the Country Club of Jackson, Mississippi, for a 10-under total of 134.
He was one stroke in front of South Africa's Tyrone Van Aswegen, who had 10 birdies in a seven-under par 65 for 135.
Van Aswegen's round also included a pair of sixes -- a bogey at the par-five fifth and a double-bogey at the par-four 16th.
But thanks to his personal best for birdies in a round he was in contention for a first tour title.
Among four top-10 career finishes on tour, Van Aswegen's best result is a tie for third at the 2015 Safeway Open. His most recent top 10 finish was a share of ninth at the 2017-18 season-opening Safeway Open earlier this month.
American Vaughn Taylor was in the clubhouse on eight-under 136 after carding a six-under 66 that included six birdies without a bogey.
Ireland's Seamus Power was eight-under with two to play when thunderstorms stopped play with 30 players still on the course.
They were to complete the round on Saturday morning.
Power is making his 27th start on the US tour and he, too, is seeking his first title.
The week in Mississippi is an opportunity for the less-heralded, with the elite of the golf world gathered at the WGC-HSBC Champions event in Shanghai.