English, seeking his first victory on the PGA Tour, turned in a 6-uunder 64 at the TPC-Southwind course and finished 36 holes at 10-under 130.
That put him two shots in front of Shawn Stefani and English was five shots in front of everybody else.
Phil Mickelson turned in a 67 that allowed him to survive the 36-hole cut in the final tuneup prior to next week's U.S. Open.
English, who turned pro two years ago, is known for maintaining a busy schedule as he tries to earn his way on the PGA Tour. This is his 17th tournament of the year and he has three top-10 finishes to his credit.
English birdied the first three holes Friday and then suddenly jumped to 5-under for the round when his second shot at the par-4 fifth, one of the most difficult on the course, landed on the front edge of the green and rolled directly to the hole. The ball barely made it over the front lip for an eagle and he went on to fire the low round of the day.
Scott Stallings, who finished tied for fourth in each of the last two stops on the tour, shared third place with rookie Paul Haley II at 135. This is only the second cut Haley has made in his 11 events as a PGA Tour member.
Nicolas Thompson, Doug LaBelle, Justin Hicks, Glen Day and 49-year-old Davis Love III were tied for fifth at 136.
Defending champion Dustin Johnson was part of the group at 137 after firing a 70. Mickelson stood at 138, having jumped 56 spots into a tie for 22nd place. John Daly also survived the cut at 140, just the fourth time he has done so in 10 tries this year.
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