Dustin Johnson’s 8-foot par putt and Hunter Mahan’s double bogey on the final hole made No. 18 the main factor on the opening day at Colonial.
With a scoring average of 4.125, No. 18 played as the fifth-most difficult hole of the day.
After a birdie on the 16th, Johnson’s par on No. 18 secured his spot atop the leader board (5-under-par 65).
“I think I hit every green but the last one,” Johnson said. “In the fairway, I got in the divot on the last hole and I thought I hit a great shot. I think it flew just on top of the bunker and if it flies another foot, it’s in there close.”
Mahan was coming off a birdie on No. 17 when he three-putted from 6 feet to end his round at 4-under 66.
“On No. 18, you have to kind of hook it off the tee with whatever club you want to do that with,” Mahan said. “It’s all about the tee shot there and putting the ball in play. You get in position, you’re going to have a wedge or something in your hands, and you can kind of be aggressive from there.”