REUTERS: Rory McIlroy and Patrick Cantlay were tied for the lead at one-under par after the second round of the BMW Championship on Friday as the Olympia Fields Country Club continued to torment the world's best golfers.
McIlroy and Cantlay were the only two players under par at the halfway point of the second of three FedExCup playoff events, where 69 players are battling it out for a place in next week's Tour Championship.
Starting on the back nine, McIlroy (69) was cruising early with three birdies and a bogey over his first nine holes but struggled coming in as conditions worsened at the course outside Chicago.
"As it got later in the day, the golf course definitely became a little firmer, a little tougher," said the world number four.
"The wind got up a little bit. A little disappointed to drop those shots on the way in, but I think if you shoot anything under par on this golf course, you've got to be pretty pleased."
Cantlay's eventful round included an eagle, four birdies, two bogeys and a double bogey as the American carded a second round two-under 68 to sit at one-under 139 for the tournament.
He said not giving into frustration was key.
"You've got to realize that you're going to make mistakes," he said.
"You're going to make some bogeys just because of how hard the golf course is, and always having a forward mindset as opposed to thinking about what's happened or what the mistakes you've made is really important."
Dustin Johnson, who is leading the season-long FedExCup standings, pumped his fist after he drained a tricky 32-foot birdie putt on his last hole to finish at even-par 140 going into the weekend.
The world number one is currently tied for third with overnight leader Hideki Matsuyama.
Tiger Woods' poor putting led to a miserable round that included five bogeys, a double bogey and two birdies for a round of five-over 75.
The 15-time major champion is currently eight-over 148 for the tournament and would need a miraculous turnaround to make the Tour Championship.
(Reporting by Rory Carroll in Los Angeles; Editing by Daniel Wallis)