CARMEL, Ind. -- U.S. Open champion Dustin Johnson ran off four birdies in his last five holes Saturday and posted a 4-under 68, giving him a three-shot lead going into the final round of the soggy BMW Championship.
Johnson couldn't make any putts early. He couldn't miss late.
His late run to seize control began with a 10-foot birdie putt on the 14th hole and ended with an 18-foot birdie putt on the 18th.
Paul Casey did his best to stay with Johnson. Casey, coming off a runner-up finish on Labor Day at the TPC Boston, matched two of Johnson's birdies during a late run until he had to scramble for pars on the last two holes. He still managed a bogey-free 68 and will be in the final group Sunday at 15-under.
Johnson was at 18-under 198.
He will be going for his third victory of the year, which would move him to the top of the FedEx Cup going into the finale at the Tour Championship in two weeks and make him a heavy favorite to win PGA Tour player of the year and the Vardon Trophy.
J.B. Holmes was still in the mix; he shot a 68 and was four shots behind. Holmes at least is making a compelling case to be a captain's pick for the Ryder Cup when Davis Love III announces three of his selections on Monday. Holmes finished 10th in the U.S. standings.
Roberto Castro, who began the third round tied for the lead, didn't make a birdie in his round of 74 and fell six shots behind. Worst yet, the Georgia Tech alum who lives in Atlanta hurt his chances of moving into the top 30 who advance to the Tour Championship.
Barring a collapse by Johnson, which has happened before, his big finish after a rain delay earlier Saturday eliminated several players. Adam Scott finally got some putts to drop, and with birdies on the last two holes, he shot a 67 and joined Matt Kuchar (68) at 11-under 205.
But they were seven shots behind after Johnson was done making birdies.
"I'm certainly a long shot. I'm a long way back of the leaders and some great names on the leaderboard," Kuchar said. "But I got a chance, and golf on Sunday in fun when you have a chance."
Jordan Spieth had such a poor day putting that the distance of his total putts added to 30 feet, 6 inches. Spieth routinely makes one putt from that distance in a round. He was helped by two chip-ins, one for birdie and one for eagle, but closing with two straight bogeys gave him a 68. He was 10 shots behind, and his attention turned to a strong finish with hopes of getting one of the top five seeds at East Lake in the Tour Championship.
Anyone in the top five only has to win the Tour Championship to claim the FedEx Cup and its $10 million bonus.
The third round already was scheduled to start late because of morning storms in the forecast, which pounded Crooked Stick and delayed that time by 1 1/2 hours. Making it tougher was the wind that pushed the clouds away and made it difficult to score.