Edfors, who has not shot lower on The European Tour since a closing 63 won him the 2006 Barclays Scottish Open, goes into the weekend ten under par and one ahead of England's Mark Foster and Spaniard Sebi Garcia.
Ranked only 1,272nd in the world, Garcia has an English mother and was born with spina bifida, but at the end of last year had a round of 58 in a Spanish tour event.
He does not have a card for The European Tour and is playing this week on a sponsor's invitation.
Both Edfors and Foster were in Korea last week and Edfors suffered badly from jetlag during his opening 70.
"I hardly slept on Wednesday night, probably just two hours, and was almost dizzy in the warm-up on the range," he said.
"On the back nine I was really, really tired and lucky to hang in there, but today I gave myself good chances and it was fun to make a few."
He birdied five of his first seven holes and had four more birdies in a matching front nine of 32.
Best of them was a two on the 231 yard seventh, where his three iron pulled up only four feet from the flag.
Foster was round in 66, making birdies at four of his last five holes and finishing with a superb three wood over the water and onto the green at the long ninth as the wind picked up.
The Worksop golfer, who has fallen away after good starts the last two weeks, said: "It was a 245 yard carry and I contemplated laying up, but it was the perfect yardage and I was playing really well."
Edfors has not won on The European Tour since Loch Lomond, but Foster has to go back seven years for his one and only success in nearly 250 events.
Overnight leader Ricardo Gonzalez, having opened with a 65, could only manage a 79 and, along with Darren Clarke, survived the cut with nothing to spare on level par.
In joint fourth place now on eight under are Yorkshire's Danny Willett and Frenchman Raphaël Jacquelin.
Willett played in the event as the world's number one amateur two years ago and had a third round 64, but two 68s on his return to the Real Club de Golf have been good enough to give him a chance of a first European Tour victory.
Jacquelin had a 67, while Ryder Cup Captain Colin Montgomerie had to settle for a 71 and two under total after dropping late shots again.
"Same old, same old, I can't finish off a round of golf," the Scot said after double-bogeying the 15th and then, having birdied the par five next, failing to get up and down from sand on the short 17th.