English's 66 yesterday had put him in a six-way tie for the lead after the first round.
However, while many around him could not match their first-round exertions, the American exceeded his efforts with a 64 - although it could have been better considering he dropped a shot at the final hole.
He made a superb start today with three birdies and an eagle in his first five holes.
Further consecutive birdies at the 15th and 16th were followed by a bogey at the last as he finished with a six-under-par 64.
Shawn Stefani was almost as impressive as he followed yesterday's 67 with a 65, including five birdies and no bogeys to move two shots behind English.
Three shots further adrift was Paul Haley as he added a 68, including three birdies and one bogey, to his first-round 67.
A shot behind was a group of four.
Davis Love III had been in the group of six at the top of the leaderboard overnight.
However, after starting on the back nine, the American dropped a shot at the 11th and although he picked up two birdies, he hit a double bogey at the par-four 17th.
The front nine included a birdie and a bogey before he picked up a valuable shot at the final hole to card a round of 70, four under overall.
Similarly, Glen Day, whose 66 yesterday was followed by a 70 comprising four birdies and four bogeys.
Justin Hicks followed up yesterday's 67 with a 69 while Doug LaBelle hit four birdies en route to a 66 to complete the group on four under.
Stuart Appleby, another of the overnight leaders, hit three bogeys and a birdie to finish with a round of 71 to move among a large group on three under.
Defending champion Dustin Johnson had started a shot behind but he had three birdies and the same number of bogeys, crucially one at the final hole to finish with a round of 70 to join Appleby.
Also on three under was Jason Bohn, who hit a 67 yesterday, had a rollercoaster round that included three consecutive birdies and bogeys as well as a double bogey as he carded a 70.
Ben Crane was one of the few to improve on their first round as he joined the group on three under.
Crane hit a 69 yesterday but three birdies and just one bogey saw him card a 68.
So too, Luke Guthrie. Four birdies and a solitary bogey guided him to a 67.