Will Strickler and Steven Lecuyer carded matching 6-under 66s on Thursday before play was called for the day at The Great Waterway Classic.
Strickler and Lecuyer were joined at minus-6 by JJ Spaun, who had completed 15 holes of the first round at Upper Canada Golf Course.
Trevor Murphy is one off the lead at 5-under 67, while Brandon Harkins was minus-5 after 12 holes when play was called for the day.
There was a 3 1/2 hour delay earlier Thursday. The afternoon wave of golfers had started to tee off, but few got very far. The second stoppage of play came at 5:10 p.m. ET, when water was accumulating on the course.
At that point, players were given the option of finishing their holes, but at 5:13 p.m. the horns blew again due to lightning in the area and players had to leave the course immediately.
The first round is scheduled to resume at 7:30 a.m. on Friday with the second round slated to begin at 11:30 a.m.
Strickler, who missed the cut in three of his five tour starts, started two groups after Lecuyer on the first tee. Strickler flew out of the gates with birdies on his first three holes.
The 27-year-old later birdied the fifth and eighth as headed to the back nine at minus-5. Around the turn, he tripped to a bogey at the 13th. Strickler bounced back with birdies at 15 and 17 to join Lecuyer at minus-6.
Lecuyer, who has missed the cut in four of his five starts this year, had a strong rally after a tough start. He stumbled to a double bogey on the second, but atoned for that mistake with birdies at three and five.
The Alberta native converted back-to-back birdie chances at eight and nine to make the turn at minus-2. Lecuyer had consecutive birdies from the 11th and again from the 15th to jump to 6-under. He parred the last two to end there.
NOTES: George Bradford and Brett Lederer both had holes-in-ones on Thursday ... The afternoon wave of tee times for round two won't tee off until at least 4:30 p.m. on Friday.