Johnson takes control in Indiana

Dustin Johnson will take a commanding lead into the final round of the BMW Championship in Indiana.

Reminiscent of when big-hitting John Daly overpowered the Crooked Stick course to surprise the golfing world with his shock US PGA win in 1991, a mix of long hitting and an red-hot putter saw the US Open champion open up a three-shot lead over England's Paul Casey.

Softened all tournament by heavy rain, the course has been at Johnson's mercy but on Saturday it was only in the final stretch where he was able to take full advantage, birdieing four of the final five holes to sign for a 68.

Casey, who was runner-up to Rory McIlroy at last week's Deutsche Bank Championship, matched his 68 to sit three shots off the pace on -15, with another big hitter J.B. Holmes a further stroke adrift after also carding a 68.

"With all the rain we got last night I struggled with the speed (on the greens) early in the round, kept leaving everything a little bit short but got a handle on it the back nine and finished off really nicely," Johnson told Golf Channel.

"I'm seeing the lines really well. The putter is working. It's just going where I'm looking. I feel like I read the greens very well. I'm making some putts this week.

"I'm not going to change anything [in his approach to the final round].

"I feel I've got a good game plan out here, be aggressive on flags when I feel like I've got a good club and a good number and other times there are a few holes you just want to make par on and keep going."

Casey meanwhile admits he faces a tough task to catch Johnson.

"To keep a clean sheet, I was very happy with," he said about his bogey-free round.

"The fact I stayed in touch is nice, but he's going to be a tough man to beat tomorrow.

"He's got maybe the best attitude in golf. When he gets on his game maybe he's the best ball-striker in golf, maybe the longest, and he showed it today."

Overnight leader Roberto Castro posted a disappointing two-over-par 74 to trail the leader by six shots with Adam Scott's 67 moving him up to tied-fifth, seven behind Johnson.

McIlroy's hopes of following up his superb performance last week with another strong showing were damaged by his one-over 73 and the Northern Irishman is tied-35th, 15 strokes off the lead on -3.

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