World number three Rory McIlroy looked to continue his winning form from last week’s Deutsche Bank Championship at the BMW Championship in Indiana by carding four birdies in his opening 10 holes before play was supended for the day.
Severe rain had flooded the course at Crooked Stick earlier in the day meaning that only 33 players managed to finish their rounds with the other 36 set to resume at 8am local time (1pm Irish time) on Friday.
Birdies at the first, fifth and sixth set the four-time major winner on his way with his recently rejuvenated putting on full show.
A slip up on the eighth in the form of a three-putt cost a bogey but McIlroy immediately recovered with a birdie at the ninth to go out in 33 shots.
A par at the 10th would be hist last action of the day as darkness brought a halt to play.
At the top of the leaderboard is American Roberto Castro who carded a 65 to sit at seven under with world number one and defending champion Jason Day a full eight shots back after a bogey-filled 73.
FedEx Cup points leader Patrick Reed managed a respectable two-under 70 while Dustin Johnson rolled in seven birdies on his way to a round of 67.
Leader Castro is hoping to make a name for himself on the same Pete Dye-designed course where long-hitting John Daly emerged from obscurity to win the 1991 PGA Championship.
He said he tended to thrive on the challenge of playing a course with danger lurking at every corner.
“I do better on tougher courses sometimes,” he told reporters. “It snaps me into focus. (On) Pete Dye courses there are a lot of shots where it’s do or die, so I think it probably helps me.
“It’s great to be one of the top 70 this year. I told myself the last two weeks really to play like I have nothing to lose. Making a bunch of birdies is a good way to start.”
Castro also said the thunderstorms that stopped play for more than three hours had drastically changed the complexion of the course.
“It was very different before and after. It was really firm before the delay. The greens were firm. And then after the delay really softened up.”