The two-stroke first-round leader has a total of 7-under 139, good for a one-stroke lead over England's Robert Rock (70).
Bradley Dredge (70) and Peter Whiteford (68) share third place at 5-under 141.
In an up-and-down round Friday, Havret made five birdies, two bogeys, and a near-disastrous double-bogey at the par-4 15th hole, which almost cost him the overnight lead.
The talk of the tournament continued to be who will earn a spot on the European Ryder Cup team next month.
"Mentally I'm strong," Justin Rose, the European Tour's eighth-ranked player, told the BBC. "I'm enjoying my golf and enjoying the challenge. Right now it looks good for me (but) I'm sure the guys (behind) will keep the pressure on so there's no relaxing."
Rose (71) joined nine others at 2-under 144, good for a tie for 13th place.