Collin Morikawa moved into a six-shot, second-round clubhouse lead at the Workday Charity Open in Dublin, Ohio as Graeme McDowell and Shane Lowry lost ground on the leaders.
Morikawa, who began the day with a one-shot lead, was four under after 15 holes when play was halted for 77 minutes due to a dangerous weather situation and after the break he added two more birdies for a six-under 66 to reach 13 under on the week.
That left the world number 29 Morikawa, whose two-day total marked the second lowest in course history, three shots clear of fellow Americans Kevin Streelman and Justin Thomas.
Morikawa, who began his day on the back nine, reached the turn at one under after mixing three birdies with two bogeys. He caught fire at the par-four second when he made the first of four consecutive birdies.
The American then needed four shots to reach the green at the par-four sixth hole, where he went on to make a bogey before play was interrupted.
McDowell meanwhile struggled throughout his second round, having started the day just three shots off the lead.
The Portrush native's round was marked by inconsistency and while he did manage three birdies, four bogeys saw him eventually sign for a round of 73 that leaves him ten shots off the pace.
Shane Lowry shot a level-par 72 to remain on three under par after a very disappointing end to his round.
The Open champion got to four under for the day by the 13th, which would have put him in the top 10, but he then hit bogey, double bogey, bogey between 14 and 16. He was two shots inside the cut mark however.
This week's event was added to the PGA Tour's calendar in place of the John Deere Classic, which was supposed to be held in Illinois but was cancelled due to state-related challenges regarding the Covid-19 pandemic.
"We talk about the course, I think it does fit my eye," Morikawa said of the Jack Nicklaus-designed layout after his round.
"I've been able to put myself, leave myself some really good numbers into approach shots. I've been keeping myself in the fairway for the most part, and that obviously helps."