Like England's David Howell on Thursday, the Frenchman aced the 186 yard seventh and, having also eagled the long third and birdied the fourth and tenth he moved into a share of fourth spot with Steve Webster.
A bogey on the next, however, returned Jacquelin to seven under par alongside Tiger Woods and four behind leader Rory McIlroy.
Spain's Alvaro Velasco, who made the cut with nothing to spare on level par, was on the same mark after posting a 65, but all the overnight leaders had yet to resume at that point.
Jacquelin fell back with a double bogey seven on the 13th - and so did Woods when he bogeyed the opening two holes.
That immediately raised doubts about the significance of his second round 66. Woods had three 65s last season and not one of them led to him ending a win drought going back to 2009.
Now he was six adrift as McIlroy set off again on the course where he lifted his only European Tour title two years ago.
The good news for Woods was that McIlroy also started with back-to-back bogeys. While the American came back with a birdie at the long downwind third, McIlroy pulled his second shot there, played a weak chip, then a strong one and by missing from ten feet a six and a third-successive dropped shot went on his card.
Sergio Garcia was the new leader at ten under after repairing the damage of an opening bogey - his first of the week - with a four on the 568 yard third.
South African Thomas Aiken remained second, although he had also kicked off with a bogey, and McIlroy was two back with Webster and France's Jean-Baptiste Gonnet.