Eddie Pepperell turned in a level par 36 to stay three ahead in the third round of the Sky Sports British Masters at Walton Heath Golf Club.
The Englishman started the day with a three-shot lead at eight under and he remained there midway through day three after making a birdie and a bogey on the front nine.
Fellow Englishman Sam Horsfield and Frenchman Julien Guerrier were at five under, a shot clear of a group of eight players.
World Number 50 Pepperell has finished in the top ten in five of his last eight events as he looks for a second win of the season and his career after his victory at the Commercial Bank Qatar Masters.
Matt Wallace missed the green on the first and a clumsy chip led to a bogey, extending Pepperell's overnight lead to four shots.
Jordan Smith missed the green in a similar spot and he also dropped a shot to fall into the group at three under.
Guerrier was beaten by the light on Friday and had to return to complete three holes of round two in the morning, dropping a shot to start the day at four under. He holed an 18-footer on the second to make the most of the par five and the lead was cut to three shots.
Smith played a nice chip on the same hole to get back to four under and Guerrier missed the green on the third and failed to get up and down, sending the lead back up to four shots.
Ross Fisher had bogeyed the first but picked the shot straight back up and when he holed a 20-footer on the fourth, he was in that group in second.
And that was just three back as Pepperell sent his tee-shot on the third right into the heather and came up 100 yards short with his second, failing to get up and down for par.
The fourth hole is almost as tough as the third but Pepperell hit a lovely approach in and holed a putt with plenty of left-to-right break to quickly re-establish his cushion.
Wallace bogeyed the fourth and Horsfield replaced him in the group in second with an excellent tee-shot to eight feet on the par three fifth.
Smith missed the green left on the fifth to fall to three under and was joined there by Horsfield who gave his birdie straight back on the sixth.
Wallace and Smith both did well to get up and down for birdies at the par five sixth and the group in second had swelled to four, although they were still four back.
Andrea Pavan made a birdie on the 14th to add to gains on the first, ninth, tenth and 11th, and Steven Brown made back-to-back gains on the seventh and eighth to make it six players at four under.
That group then became eight when Horsfield birdied from six feet at the seventh and Julian Suri completed a hat-trick of birdies from the sixth after double-bogeying the third.
Guerrier was the man to leap out of the pack, holing a lengthy putt on the eighth to edge himself back to five under.
Wallace then put his second at the eighth to tap-in range and he was back where he started the day - three behind Pepperell.
Horsfield joined him there with a brilliant tee-shot into the par three ninth and Wallace failed to get up and down on the same hole to drop back into the group four off the lead.
Trevor Immelman was there with birdies on the ninth and 11th after going birdie-bogey on the second and third, as was Alexander Björk, who recovered from a double-bogey on the third with birdies on the fifth, sixth, tenth and 11th.
Wade Ormsby and Marcus Kinhult were at three under.
