Marcus Kinhult fired a stunning round of 65 to set the clubhouse target on day two of the HNA Open de France.
Le Golf National had bared its teeth in high winds on day one and while conditions were more favourable for the elite field gathered for the third Rolex Series event of the season, Kinhult's round was the best of the week so far by two shots.
That moved him to six under, a shot clear of overnight leader Bradley Dredge and two ahead of Spaniard Jon Rahm, who signed for a 69.
Welshman Dredge had a birdie in his opening two holes in the second round.
England's Matthew Fitzpatrick was in the clubhouse at two under, alongside a group of afternoon starters who were attempting to chase down the leader.
Kinhult finished third at the Commercial Bank Qatar Masters but has made just three of eight cuts since, although one of those was a tie for 12th at the BMW PGA Championship.
The Swede started his round on Thursday with four straight bogeys but is ten under for his last 32 holes.
He birdied the second, made an eagle on the par five third and then picked up another shot on the fourth to very quickly jump into a share of the lead.
Two pars followed but when the Challenge Tour graduate holed a 20-footer on the seventh, he was the first man this week to get to five under.
A stunning tee-shot into the par three eighth then left him five feet for another birdie and he made no mistake to lead by two.
A 15-foot putt on the 13th had him three ahead but he made a first bogey of the day after finding trouble off the tee on the next.
A lovely approach into the 17th had the 21 year old back at seven under but he could not get up and down on the last and dropped a shot.
Rahm had a roller coaster on the back nine, sandwiching birdies on the 11th and 13th with a bogey on the tenth and a double on the 15th to turn in 36.
He went birdie-bogey on the first and second but then played the third perfectly, hitting the green in two and holing a 15-footer for eagle.
A run of four pars followed before the 23 year old put his tee-shot on the eighth to ten feet for a fourth birdie of the day.
Playing partner Fitzpatrick birdied the 11th but surrendered a double on the next before picking up further shots on the 13th, 14th and 17th to turn in 33.
The 23 year old was clearly distracted by something in the crowd as he played his tee-shot on the par three second but that did not stop him putting it to six feet for a birdie to get to three under.
A bogey on the seventh then slipped him back to two under.
World Number Two Justin Thomas, South African Dean Burmester, England's James Morrison and Belgian Thomas Pieters were two under out on the course.
Ireland's Paul Dunne, Englishman Tyrrell Hatton, Finn Mikko Ilonen and Spaniard Pedro Oriol were at one under, a shot clear of two more Spaniards in Sergio Garcia and Nacho Elvira, Swede Alexander Björk and South African Dylan Frittelli.
