Scotsman Richie Ramsay retained his two-shot lead at the Andalucia Masters despite a one-over-par 72 in round two.
Ramsay dropped three shots to slip to five under, with Gregory Havret second.
Sergio Garcia, who won last week's Castello Masters, carded a second successive 70 to go third, chipping in at the 11th for the second day running.
Justin Rose bogeyed three consecutive holes from the 15th but a 71 left him in a share of sixth, while Graeme McDowell is tied 21st following a 73.
Ramsay, a self-confessed Garcia fan, dropped shots at the two par-threes on the front nine and bogeyed the last after driving into the rough.
"Going up against one of your idols on a course, this is a dream situation," he told European Tour radio.
"It was a really tough day and I hung in there. It just illustrates how good my six under round was. I hit so many fairways and so many greens, but couldn't get the ball to drop. But my ball-striking was good and I've got to take the positives out of it."
Havret also bogeyed the final hole, and for the second day running took seven at a par-five, this time the 11th. "This course does not accept any errors. Every hole is a real challenge and you have to focus on every shot," he said.
Garcia, who needs another victory to qualify for next week's WGC-HSBC Champions in Shanghai, dropped only one shot on day two and said: "I could have been a little bit more aggressive with a couple of putts coming in, but my short game is pretty good right now.
"It was difficult to hit fairways and to choose the right club. Thank God it's soft because, if not, this would be hell. But I've always enjoyed hard courses. Back-to-back wins would be a great thing, but I don't want to get ahead of myself.
"Valderrama can catch you any time - you can never think that you have this course under control. Even without wind it's asking you to hit all the shots in the bag.
"That's the beauty of if. A course doesn't need to be long to be tough."
Ryder Cup player Ross Fisher, who has failed to record a top-five finish this season, began round two tied for fourth but returned a 79, with eight bogeys and no birdies, to drop into a share of 21st with McDowell and former world number one Martin Kaymer.
European Ryder Cup captain Jose Maria Olazabal made his first cut in nine starts, squeezing in on seven-over.
But former World Boys champion Nick Dougherty, now ranked a lowly 837th, finished last after adding an 80 to his first day 84 for a 22-over total.
The 29-year-old suffered a quadruple bogey nine at the 11th plus two double bogeys and has survived only one cut in his last 29 tournaments.