Jacquelin was runner-up at the Portuguese Open earlier this month
Frenchman Raphael Jacquelin shot a four-under-par 67 to pull clear at seven under after the second round of the Volvo China Open in Shanghai.
(GB & Ire unless stated)
-7 R Jacquelin (Fr)
-5 A Blyth (Aus)
-4 A Romero (Arg), S Hend)
-2 G McDowell, C Hanell (Swe), M Brier (Aut)
The joint-overnight leader holds a two-shot lead from Australian Adam Blyth after carding five birdies, with three in the first three holes.
Blyth is a shot clear of compatriot Scott Hend and Argentine Andrew Romero, whose 67s moved them to four under.
Thai-based Scot Simon Yates returned a 66 to go third on three under.
Markus Brier of Austria, Swede Christopher Hanell and Northern Ireland's Graeme McDowell are all poised to mount a weekend challenge from two under, along with Irishman Damien McGrane.
Jacquelin admitted he was keen to make the most of the morning calm to pull away from the pack as the weather worsened later in the day.
"I tried to make all the opportunities early on and save pars," he said.
"Like yesterday, I made two bogeys at the end but that is the game, especially on this course in these rough conditions.
"I am confident with my game at the moment but I have to make sure I make more birdies than bogeys."
Blyth, meanwhile, started steadily and even his bogey at the par four 13th, his fourth hole, had a stroke of luck about it.
"I holed it from the rough, it was looking like seven or eight," said the 25-year-old.
Experienced Scot Yates hit five birdies in his flawless 66 and said he thought it could have gone even lower.
"It's easy to make mistakes here. It is a tricky course," said the 37-year-old. "On the back nine, it could have been a few better as I had a couple of lip outs as well."
Huang Mingjie, who shared the overnight lead with Jacquelin, hit six bogeys for a 76 to drop out of contention.
He did at least make the cut, which was set at five over, unlike 18 of his 24 fellow Chinese in the draw.
Teenager Han Ren, however, became the first local amateur and the first qualifier to make it to weekend play since the event became co-sanctioned by the European Tour in 2004.