Eddie Pepperell carded a brilliant 69 in very tough, windy conditions to set the clubhouse target on day two of the Sky Sports British Masters at Walton Heath Golf Club.
The home favourite entered the second round with a share of the lead and moved to eight under, five shots clear of his closest challengers to have completed 36 holes.
Defending champion Paul Dunne, Malaysia's Gavin Green, Frenchman Mike Lorenzo-Vera and England's Matt Wallace were four under in the very early stages of their rounds, with Dane Lucas Bjerregaard and English pair Ross Fisher and Sam Horsfield in the clubhouse a further shot back.
Alexander Levy had a hole to complete in the moring after play was suspended due to darkness on Thursday night and he birdied the last to move into a share of the first-round lead.
Pepperell broke out of that group with a birdie on the 11th but Levy made a gain on the same hole before Pepperell holed an 18-foot left-to-righter on the 14th to get to seven under.
The Commercial Bank Qatar Masters champion made a first bogey of the day on the 15th and when Levy put his approach to the 14th to eight feet, there had been a swap at the top.
Pepperell then hit back with an approach to six feet on the last and the duo were tied.
The 27 year old did well to save par on the second after finding some nasty heather off the tee but Levy could not do the same on the par three 17th, missing the green and then flying his second over the putting surface and into a bunker en route to a double-bogey.
That put Pepperell two ahead and he soon extended that lead to three thanks to a brilliant chip-in on the third.
Levy fell back as he played the front nine in 42 and that meant Wallace - who was yet to tee off - was the closest challenger.
A three-putt from Pepperell on the seventh saw the lead cut to two but a stunning approach to the eighth re-established his cushion as he set the target at eight under.
Wallace started his round with a par but sank a putt from close to 100 feet on the second to quickly cut the lead to two. The four-time European Tour winner then found a nasty lie with his second and another bogey on the fifth extended the lead to four.
Dunne spun his third on the par four third into the hole and then made an excellent left-to-righter on the next to get within four of the lead.
Green birdied the tenth while Lorenzo-Vera was level par after three holes.
Bjerregaard was among those five back after he signed for a 67 that was the lowest round of the day so far.
Last week's winner went birdie-bogey on the 11th and 12th before pitching his second on the par four 15th straight into the hole for an eagle and making further birdies on the second, fifth and seventh.
Horsfield made five birdies and three bogeys in a 70, while Fisher signed for a level par 72.
Shane Lowry made the 34th hole-in-one of the season and second of the week as he holed an eight iron from 170 yards on the fifth, the ball pitching next to the flag and taking one bounce into the hole.