Tom Kim of South Korea and Erik van Rooyen of South Africa had one hole left to break out of a four-way tie for the lead when first-round play at the Charles Schwab Challenge was suspended due to a dangerous weather situation on Thursday in Fort Worth, Texas.
When play was delayed at Colonial Country Club, Ryan Gerard and Andrew Putnam were in the clubhouse with 6-under-par 64s while Kim and Van Rooyen were 6 under with the par-4 ninth hole left to play.
The tournament was suspended at 4:15pm local time and it was not clear whether it would resume on Thursday.
Many groups from the afternoon wave had between one and nine holes left to play.
A 10-man logjam at 5 under par included Keegan Bradley, Brian Harman and Alex Smalley in with scores of 65, while J.J. Spaun, Gary Woodland and Lee Hodges were 5 under with some holes to go.
Max Homa, Russell Henley and Japan's Hideki Matsuyama highlighted the 12-man clump at 4-under 66.
Putnam, who had a bogey-free day, seeks his second PGA Tour victory and his first since the 2018 Barracuda Championship. Gerard's only win on tour, coincidentally, came at the Barracuda Championship last year.
He mixed eight birdies with two bogeys on Thursday.