Alexander Levy set the clubhouse target at the Real Club Valderrama Open de España, Hosted by the Sergio Garcia Foundation on a day of typically tough scoring in Andalucía.
Just ten of the morning starters managed to record an under par total on Thursday, and it was two-time European Tour winner Levy who led the way as he set the target at five under.
That was enough to give the Frenchman a one-shot lead over Andrew Johnston and Stuart Manley, with Jordi Garcia Pinto, Joakim Lagergren, Martin Kaymer and Richie Ramsay a further two shots back.
Levy opened with a birdie on the tenth and added to it on the 12th before dropping a shot on the 13th. In a topsy-turvy first nine, he then made further gains on the 14th, 15th and 17th before making a second bogey of the day on the 18th.
Birdies followed on the first and second to get Levy to five under and none of the morning starters could catch him as he parred his way home.
Englishman Johnston made back-to-back birdies on the fourth and fifth and added to those gains on the 11th and 17th as he fired the only bogey-free round so far.
Manley, a five-time Qualifying School graduate, had set the target around an hour earlier thanks to a brilliant second nine of 31.
He started on the tenth and was level par after his first nine but then went on a sensational run, picking up shots on the first, second, fourth, fifth and sixth before a bogey on the eighth dropped the Welshman out of the lead.
Swede Lagergren had an eagle on the fourth on his way to a 69 but two-time Major Championship winner Kaymer did not fare so well on the par five, the German making one of his two bogeys after finding the hazard to the right of the green.
Home favourite Garcia Pinto had five birdies in his round with three bogeys, while Scot Ramsay recovered from a double-bogey on the eighth to also sit at two under.
Maximilian Kieffer and Rhys Davies also overcame doubles to sit at one under alongside Ross Fisher, who had 15 pars in his 70.
Søren Kjeldsen, a previous winner at Valderrama, was then at level par with Tommy Fleetwood, Lee Slattery and Craig Lee, the Scotsman having held a share of the lead at five under before dropping five shots in his last six holes.
Tournament host Sergio Garcia, who has ten top tens in 11 events here, was three over after an opening 74.
