Graeme Storm put himself in sight of a maiden European Tour title when the Englishman led the Spanish Open at the halfway stage by a stroke.
Storm birdied his last three holes to retain the top place he had shared after the first round with Portugal's Jose-Felipe Lima, carding a five-under-par 67 to move to 12-under-par 132.
Storm's playing-partner Robert Karlsson holed in one at the fourth on his way to breaking the San Roque New Course record by a shot with a 63, to be one of five men sharing second place.
Earlier, Denmark's Thomas Bjorn shot 64 to break the record set originally by Storm and Lima, to lie two strokes off the pace and kick-start what has been a troubled season.
After Storm won the British Amateur title in 1999 and played in Britain and Ireland's winning Walker Cup team the same year, much was expected of the 28-year-old but he had found little success until finishing second in last year's European Open.
Now he can complete a turnaround in his career with a first victory. "I think most people thought as British Amateur champion you should go on to great things but it takes a lot of hard work and dedication," said Storm.
Bjorn, who famously lost the 2003 British Open after leading by three strokes with four holes to go, is battling back after recurring neck problems which flared up in early February caused him to miss what he considered a vital stage of the year and dropped him from 22nd on the world rankings to 34th.
He said: "After Dubai (the Desert Classic) I went five weeks when I literally didn't touch a club and it wasn't much fun because you feel like you are losing out.
"It's a time when players get themselves ready for the big tournaments. But today was one of those days when golf seems easy."
Bjorn said he would not be playing this year's European Open in July, even though the K Club will be staging the Ryder Cup in September, because of "too many bad memories."
South African Titch Moore, trying to regain his tour card, Spain's Carl Suneson and two more Britons, David Griffiths and John Bickerton, share second place with Karlsson.
Australia's David Bransdon also holed in one, acing the eighth to shoot a 65 and lie eight-under with tournament favourite Colin Montgomerie.
