HOYLAKE, England — With his thinning hair and his thickening waistline, Butch Harmon has a way of blending into the crowd when he follows his players’ competitive rounds on foot. On Saturday at the British Open, though, there was no missing him.

Early in the third round at Royal Liverpool, players whom Harmon teaches occupied the three spots directly behind the pacesetting Rory McIlroy: Dustin Johnson was holding down second, Rickie Fowler was third, and Jimmy Walker was tied for fourth.

By day’s end, Fowler stood second, six strokes behind McIlroy after posting a four-under-par 68, his third sub-70 score, for a 54-hole total of 10-under 206. One stroke behind Fowler, in a tie for third with Sergio García, was Johnson, who carded a 71. Walker was tied for 12th, at five under, after posting a 71.

Another Harmon pupil, Phil Mickelson, was one under and tied for 34th in his defense of the title he won last year at Muirfield.