Canada's Taylor Pendrith, Argentina's Alejandro Tosti and US golfers Keith Mitchell and Ryan Gerard shared the lead on Thursday when darkness halted the first round of the PGA Houston Open.
All four fired a five-under par 65 at Memorial Park before sunset stopped play on a rainy day with 18 competitors still on the course to complete their opening round on Friday morning.
Top-ranked Scottie Scheffler, in the final tuneup event before he defends the Masters title next month, fired a bogey-free 67 to stand two adrift.
"I started to play a little bit better on the back nine. The first nine I was kind of getting it around a little bit, but still post a score," he said.
"Conditions were pretty tough out there with the rain and the wind, so overall nice to keep a clean card."
World No 2 Rory McIlroy, the Players Championship and Pebble Beach Pro-Am winner who needs the Masters to complete a career Grand Slam, had two birdies and two bogeys in a first-round 70.
"A little pedestrian I guess is a good way to describe it," McIlroy said.
"Had to deal with those conditions early on, rainy and not too pleasant to play in. Made a few par saves early on that I needed to and then had quite a few chances on the second nine that I didn't convert."
The only player within two strokes of the lead not to finish was Taylor Dickson. The American was three-under with three holes remaining.
Pendrith, whose only PGA title came at last May's CJ Cup Byron Nelson, would have led alone but made his only bogey at 18 after finding a greenside bunker and missing a nine-foot par putt.
His six birdies included a 42-foot putt at the par-4 fourth and another from just inside 24 feet at 17.
"I played pretty good. Difficult day, rain was on and off and got gusty for us," Pendrith said. "Hung in there nicely, didn't make too many mistakes and drove the ball really well. Saw a couple nice putts go in early and gave me some confidence. It was a great start."
Tosti's bogey-free round included a 22-foot putt at the par-5 third and a tap-in at the par-5 16th.
"Very pleased with the result," Tosti said. "I played very solid."
Another player seeking like Tosti his first PGA title is Gerard, a rookie whose best tour result was fourth at the 2023 Honda Classic. The back-nine starter birdied four of his first eight holes only to close his round with back-to-back bogeys.
"Played really solid, just a weird couple things on the last two holes," Gerard said. "It's not easy when it's raining and then windy and then off and on with the umbrella and ball's kind of squirting off the face of the golf club.
"Really tried to stay patient. That was the key to the day."
Mitchell, whose only PGA win came at the 2019 Honda Classic, grabbed his share of the lead with a 12-foot eagle putt at 16.
"Hopefully I can stay sharp and keep it rolling this week," Mitchell said.