Sergio Garcia is on course for back-to-back victories after a dramatic finish to his Andalucia Masters third round.
Garcia took off his shoes and socks and rolled up his trousers to play out of the hazard on 17, but failed to make par, before sinking a birdie on 18.
The Spaniard carded a four-under-par 67 to move to six under par, two strokes clear of compatriot Miguel Angel Jimenez and Sweden's Christian Nilsson.
Richie Ramsay, the overnight leader, shot a 73 and is three off the lead.
Garcia, who ended a three-year title drought last weekend with an emphatic 11-shot victory , said: "It's going to be much harder than last week, so I'm not going to get ahead of myself.
"Playing out of the hazard on 17 was risky but I thought I had a better chance to make par than playing from the [penalty] drop zone. I just didn't trust my putter as I should have."
Playing-partner Jimenez made two eagles - a pitch in on the fourth and an 18-incher on the 11th after a stunning approach - in his 68.
"I could have had birdies on the 15th, 16th, 17th and 18th," said Jimenez, who is looking for a first win of the year. "If I could get my putter at least warm I may still have a chance."
Nilsson increased his chances of qualifying for Shanghai with the joint-best score of the week, sinking eight birdies, including four in succession from the fourth, in his 65.
"It's the most important day of my career tomorrow," he said, "and this was the best round of my career."
Even with world number one Luke Donald deciding not to play in next week's Champions event in Shanghai, German Martin Kaymer's chances of retaining his European number one status receded with a 73 that left him 12 strokes off the lead.
Donald withdrew from the tournament in China with the birth of his second child imminent.