Eduardo De la Riva, who competes on the Spanish regional tour, shot a 4-under 68 Saturday for a one-stroke lead after three rounds of the Andalucia Open.
He was at 12-under 204 going into the closing round on the Aloha course. A stroke behind were 18-year-old Italian Matteo Manassero (68) and England's Simon Khan (66).
The Andalucia Open is only De la Riva's ninth European Tour appearance in four years, with all but one contested in his homeland. He will earn a one-year European Tour exemption if he wins.
''I've come here to try and win and I won't throw the towel in before the tournament finishes,'' he said. ''I will try to be as relaxed as I have been the other days.''
Eighteen players are within four strokes of the lead. Two strokes behind are England's David Lynn (68), South Africa's Henni Otto (68) and tournament host Miguel Angel Jimenez (69).
Manassero kept alive hopes of qualifying for next month's Masters with a round that included five birdies, but he lost a share of the lead with a 16th-hole bogey. Manassero competed in the 2009 Masters as the British Amateur champion but has yet to play there as a professional.
Ranked 63rd, he needs to win or finish second Sunday and in next week's Hassan II Trophy in Morocco to qualify for Augusta as a top-50 player.
''I am still right in this event and right where I wanted to be,'' Manassero said. ''I played really well and, funny, my round of 68 was ever better than my 64 on Thursday as my game was a lot more solid from tee to green.''
Khan capped his 66 with three straight birdies from the 10th hole. It was his lowest score since a 66 during July's Scottish Open.
Jimenez had two bogeys in his opening six holes. He regrouped with a birdie on the 10th and a run of birdie, birdie, eagle from the 14th.
''I started out like a donkey, but finished like a racehorse,'' he said.
