Julien Guerrier stayed bogey-free at Verdura Golf Club to set the clubhouse target on day two of the Rocco Forte Sicilian Open.
The Frenchman carded a 65 to get to nine under in Italy and was the only player in the field yet to drop a shot over two days in testing, windy conditions on the coast.
English pair Steven Brown and Ryan Evans were a shot behind, with another Frenchman in Mike Lorenzo-Vera then at seven under.
Guerrier regained his playing privileges via the Challenge Tour last season after graduating from the Qualifying School in 2009 and 2011 and is already on course for his best season on the European Tour.
His third-place finish at the NBO Oman Open was his best result since the 2014 Madeira Islands Open – Portugal – BPI and one of two top tens this campaign as he goes in search of a first European Tour victory
Co-overnight leader Evans made a fast start with birdies on the second and third but gave the shots back on the fourth and sixth before making further gains on the seventh and ninth to get to eight under.
Fellow Challenge Tour graduate Brown made birdies on the 12th, 14th and second and, when he added back-to-back gains on the fourth and fifth, he was in a share of the lead.
He held it on his own after an Evans bogey on the tenth but a nice chip from the 31 year old had him back in a share, before a Brown bogey on the eighth put Evans back in top spot alone.
Brown was soon joined by Guerrier in second as the 32 year old sandwiched an eagle on the second with birdies on the 12th and third but Brown edged back ahead of him after a nice chip on the ninth.
A par on the tenth then saw Brown set the target for the rest of the field at eight under.
Lorenzo-Vera was soon just one back of that as he made an impressive charge through the field. After a birdie on the 13th, he made five in six holes from the 16th, including a stunning approach into the wind on the third. Another smart second into the difficult sixth brought a seventh gain of the day and he was seven under.
Guerrier had made three pars in a row but he hit an excellent tee-shot into the very windy par three seventh and joined the lead with a birdie, as Evans dropped out with a bogey on the 17th.
The leading group was not down to two for long, however, as Lorenzo-Vera took advantage of the par five ninth and Evans bounced back with a gain on the last from 15 feet to make it a four-way tie.
Guerrier was the next man to make a birdie on the ninth as he broke out of the leading logjam, with Lorenzo-Vera recording a disappointing closing bogey on the tenth.
Joakim Lagergren recently finished in a tie for third at the Trophée Hassan II and he was five under for the day through nine holes after birdies on the 11th, 12th, 14th, 16th and 17th. Another birdie on the third edged him closer to the lead but he got in trouble down the left and dropped a shot on the tenth that left him five under.
England's Marcus Armitage, Dane Lucas Bjerregaard and Spaniard Scott Fernandez were also five under in the early stages of their second rounds.
Francesco Laporta and Andrea Pavan delighted the local crowds as they moved into contention at four under. Laporta turned in 33 but then dropped a shot on the tenth in his 69, while Pavan dropped a single shot in a 66.
England's Paul Waring was also four under, a shot ahead of Finn Mikko Korhonen, who finished his round with a spectacular birdie putt from over 50 feet on the tenth.