Chicago, September 9

Roberto Castro fired a seven-under par 65 to grab a one-stroke lead over fellow American Brian Harman after darkness halted Thursday’s opening round of the US PGA BMW Championship.

Castro, seeking his first PGA title, birdied the second and fourth holes and added another at the par-5 ninth for a solid start, then birdied six of the final nine holes only to take a bogey at 18 to halve his edge.

Lightning and heavy rain in the Indianapolis area stopped play for three hours and 31 minutes, leaving the late threesomes in the field of 70 no hope of finishing before sunset.

In all, 36 players were forced to conclude their first rounds on Friday before an early start to the second round in hopes of completing play before storms return to the 7,516-yard Crooked Stick layout. All players completed the front nine except Australia’s Aaron Baddeley, who has a 13-foot eagle putt at the ninth when play resumes.

US major champions Dustin Johnson and Jason Dufner shared third on 67 with compatriot Chris Kirk, who had the back nine yet to play.

Argentina’s Fabian Gomez was in the clubhouse on 68 with Japan’s Hideki Matsuyama at four-under with six holes to play and England’s Paul Casey and Australian Adam Scott on four-under with eight holes remaining.

Top-ranked Aussie Justin Day opened on 73 with six bogeys and five birdies. Third-ranked Rory McIlroy of Northern Ireland was three-under after 10 holes. He opened with a birdie and had tap-in birdies at the par-5 fifth and ninth.

He made a five-footer for birdie at the par-3 sixth but missed a six-footer for par at eight.

Castro has a pair of runner-up PGA finishes for his top showings, at Congressional in 2013 and this year at Quail Hollow. Castro sank a 17-foot birdie putt at the second and drained a stunner from 54 feet to birdie the fourth, but the highlight shot of his round was a 41-foot chip-in birdie at the 14th.