Daniel Brown produced another brilliant round to blitz the field and storm into a six-shot lead at the ISPS HANDA World Invitational presented by AVIV Clinics.
The 28-year-old carded the lowest round of his DP World Tour career with a 64 in the first round at Castlerock to lead by two shots at the event that is co-sanctioned by the LPGA Tour and Ladies European Tour where full fields of men and women play across two courses over the four days.
But Brown, who was one of the afternoon starters at Galgorm which played considerably harder on Thursday, surged ahead of the distant chasing pack following his superb four under par 66.
A roller coaster front nine contained four birdies and three bogeys before he powered ahead with three more gains to sit six clear of Spaniard Angel Hidalgo and Englishman Alex Fitzpatrick at the halfway point in Northern Ireland.
"I've just been taking it one shot at a time. I know it's cliché, but obviously it's been so tricky at times, with the wind and rain today as well," Brown said.
"I suppose you just work out the shots as best you can and then try and execute it. Thankfully, I have done it a few times over the last couple of days.
"I think the last two events, Denmark and then the Barbasol in America, had two good finishes there and I felt like I've done enough to keep my card for next year. It feels as though the shackles are off a little bit.
"Obviously it's my first year out here, so I've been trying to put that to the back of my mind, and obviously do as well as you can each week, but I feel like I'm just going out and enjoying it a bit more now, a little bit more carefree, I suppose."
Hidalgo set the early clubhouse target at five under par, before Brown even started his second round, following his 69 at Castlerock, which consisted of five birdies and three bogeys.
Fitzpatrick, who sat two shots behind Brown after round one, bounced back from a two-over front nine at Galgorm with three gains and only one dropped shot for a battling level-par 70.
English pair Eddie Pepperell and John Parry lead the five strong group at three under alongside Spaniard Adrian Otaegui, Scotland's Connor Syme and Norway's Rasmus Neergaard-Petersen for a share of fourth.
Brown continued where he left off on Thursday when he rolled in a birdie at his opening hole - the tenth - to make instant improvement to his lead.
His advantage was soon cut to one after he carded back-to-back bogeys from the 13th to drop to six under, with Hidalgo, Portugal's Ricardo Santos and Italian Gregorio De Leo trailing behind.
However, he immediately bounced back with successive gains at the 15th and 16th before a bogey-birdie finish on the front nine saw him remain at eight under with a three-shot lead.
Brown rolled in his fifth birdie of the day from close range at the second to improve to nine under and when he drained a monster putt at the next, he was the first person to reach ten under for the tournament.
He lipped out another chance at the fourth but took his next opportunity at the fifth to make it three birdies in four holes to climb to 11 under and sit six clear of the field, which he maintained as he parred his way home.
Hildalgo began Friday at three under and improved his score with a birdie at the first, only to drop back following successive bogeys at the third and fourth.
He picked up another shot at sixth but reached the turn with a bogey at the ninth. However, the 25-year-old was flawless on the back nine with gains at the 11th, 15th and the last to climb to five under.
Fitzpatrick showed his grit to remain in contention after he slipped to three under after dropped shots at the fifth and ninth.
The Englishman birded the 11th and 16th to return to five under, only to bogey the penultimate hole drop back a further shot. Fitzpatrick then laid up at the par-five last and when he rolled in his third gain of the day, he grabbed a share of second place.
All five players sharing fourth place were at Castlerock for their second rounds, with Pepperell and Otaegui carding three under 68s while Parry, Syme and Neergaard-Petersen all posted 69.
Portuguese duo Pedro Figueiredo and Santos, India's Manu Gandas, Richard Mansell, Japan's Rikuya Hoshino, Frenchman Robin Sciot-Siegrist and Sweden's Niklas Lemke sit nine shots off the lead at two under.
In the women's event, America's Marissa Steen led the way at three under par, one clear of Germay's Esther Henseleit, where only seven players were in the red numbers at the halfway point.
