Dustin Johnson surged during the second round of the BMW Championship on Friday, shooting a bogey-free nine-under par 63 that included two eagles, and is tied with Roberto Castro for the lead at Crooked Stick Golf Course in Carmel, Indiana.
Castro, looking for his first PGA Tour win, shot a second-straigh seven-under 65, this one bogey-free. He and Johnson lead Paul Casey by three strokes.
J.B. Holmes, a Ryder Cup hopeful, shot a seven-under 65. He is tied for fourth place with Chris Kirk at 10 under.
Matt Kuchar, the Olympic golf bronze medalist, is tied for sixth at seven under with Sergio Garcia, Kevin Na and Ryan Palmer.
Jason Day, the world No. 1 and defending champion, is four under and tied for 19th with Rory McIlroy, Jordan Spieth, Russell Knox and FedEx Cup points leader Patrick Reed.
McIlroy, last week's Deutsche Bank Championship winner, shot an even-par 72 in a round that included four bogeys. Spieth's round was also an even-par 72, with four bogeys and a double bogey.
Phil Mickelson shot a one-over 73, dropping back to three under for the tournament. He is tied for 35th and 11 shots off the lead.
Rickie Fowler continued to disappoint in attempting to make his Ryder Cup case, and is at two over entering the weekend. He is tied for 62nd, 16 shots off the lead.