Englishman Lee Slattery remains on course for the Madrid Masters title after a three-under par round of 69.
The Southport-born golfer finished the day two shots clear at 14 under par.
Brett Rumford and Lorenzo Gagli are now his nearest rivals after they moved to 12 under with rounds of 68 and 69 respectively.
World number one Luke Donald is also still in with a chance of retaining his title, but six shots stand between him and Slattery.
Donald had to endure a frustrating finish to his round - he dropped shots at three of the last five holes, including hitting in to the water with his approach to the 18th.
His putting was also a little wayward, missing a four-foot chance for birdie at the 13th and sending a three-foot putt past the hole at the 14th. Despite the missed opportunities the Englishman refused to rule himself out of successfully defending his crown.
"I'll need to go really low tomorrow, 64 or 65, which can be done on this course," he said. "But I'm going to need some help from the field.
"I've missed a bunch of putts, from six or seven feet, inside five feet. I've struggled with the reads and the pace."
Despite Rumford and Gagli moving into joint second they had contrasting rounds, with Rumford shooting a consistent 68 that included five birdies and only one dropped shot, while Gagli picked up an eagle and five birdies but also carded four bogeys in his 69.
Eduardo De La Riva was leading at the halfway point of the third round, but Slattery produced a steady round of three birdies without dropping a shot.
Slattery, who is chasing his debut win on the European Tour, said after his round: "It's been tough this year so there's obviously a little bit of pressure on me tomorrow. Somehow I've got to be able to relax.
"It's going to be all about switching off tonight and not worrying about it."
Italian Gagli is seeking to emulate compatriot Matteo Manassero by winning a title in his first season and going on to capture the award for Europe's rookie of the year.
The 25-year-old lies 49th on the money-list after a third place and three top-five finishes - and he believes a session with Ryder Cup captain Jose Maria Olazabal in April has helped him improve.
He said: "We spent five days together in Italy and I learned such a lot from him, he is such a good coach and a gentleman. It improved my golf so much."