Dredge recovered from an early setback when his wedge at the third hole spun back into water to card six birdies on a morning when occasional rain showers made concentration difficult.
He then raised the issue of Wales being represented in Europe's team for the Ryder Cup in September when the principality will host America at Celtic Manor.
Until recently that has seemed a remote prospect since the host country currently doesn't have a single player ranked among the top 80 players in the world.
However, after Welsh rookie Rhys Davies impressively won last week's Trophee Hassan II in Morocco, Dredge believes a rivalry between the pair could improve that situation.
"I will only have one chance during my career to play in the Ryder Cup in my own country, so that is my ambition for the year," said Dredge, who recorded the last of his two European Tour victories at the European Masters in 2006.
"But to do that I have got to win several tournaments and it would be good to start off by winning here in Andalucia at the weekend. Seeing Rhys Davies win in Morocco has given me an extra drive. It was good to see a Welshman win, but I want to stay ahead of him and hopefully that will lead to a friendly rivalry that will fire us both up." Another remote possibility is that Europe captain Colin Montgomerie would pick a fellow Scotsman in his team of 12.
An hour after Dredge signed for his score, 1999 British Open champion Paul Lawrie moved into the lead at 5-under with a 65.
Lawrie recently returned to coach Adam Hunter, with whom he worked during his victory at Carnoustie, and he had special reason to be pleased with his score. Hunter was recently diagnosed with leukemia and Lawrie said, "That should help cheer him up a bit." Sharing second place at 4 under with Dredge were Julian Guerrier of France, Mark Brown of New Zealand and Joost Luitn from the Netherlands.
