Swedish trio Richard Johnson, Olle Karlsson and Carl Pettersson, Spain's Jose Manuel Lara and Germany's Erol Simsek were in a tie for second on five under, with another Swede, Mikael Lundberg, alongside Blackey a further stroke adrift.

Blackey said: "I bogeyed the first mainly because I couldn't see the fairway because of the fog!

"It was coming in waves and standing on the range I though it would be okay, but when I got on the tee you couldn't see more than 200 yards."

A birdie from eight feet on the third got Blackey back to level par and further birdies from 30 and 15 feet on the fifth and seventh took him out in 32, two under par.

Two more birdies on the inward nine completed his 66 and carried on his form from last week in Sao Paulo when he finished joint eighth.

"It's been a good couple of weeks and hopefully I can keep it going for another three days," added Blackey, who lost his card after finishing 126th on the Order of Merit last year.

"I played a bit scrappy but it's that kind of course because it's so tight. But the short game was on fire, I only had 25 putts and it always helps when the wand is working.

"With losing my card I don't know when I'm going to get into tournaments so it's nice to do well because it can help when you ask for invites and, including Morocco, it will be good to play five weeks in a row as it gives you a chance to get the game in order."

Leader Franco carded seven birdies and one bogey in his superb 64 that gave him a one shot lead over the field.

Franco, whose brother Carlos plays on the USPGA tour, revealed he had his son to thank for his improved display, saying: "I had surgery on my spine two years ago and changed my swing because of that.

"I was a little lost so I watched some old videos from the time I was playing well and wondered why.

"My son, who is also a professional, then told me that in the past my stance was much more open. I've been practising that for a couple of days and am hitting the ball stronger and I'm more comfortable."

Defending champion Vicente Fernandez carded a one-under-par 69 while the man he beat in a play-off 12 months ago, compatriot Eduardo Romero, had to settle for a level-par 70 in the event he helps promote.

Sheffield's Neil Cheetham, joint eighth with Blackey in Sao Paulo last week, continued his good form with a two-under-par 68, a score matched by Londoner Anthony Wall and former amateur champion Graeme Storm.