Ignacio Garrido three-putted the last to take a three-stroke lead into the final round of the Spanish Open in Seville tomorrow.
The 36-year-old, just 19 days old when his father Antonio won the title in 1972, followed up his course record 63 with only a level par 72 and so remained 15-under-par.
Denied the title by Seve Ballesteros in 1995, Garrido faced another Spanish showdown, with his nearest challenger Miguel Angel Jimenez.
Eighth in The Masters a month ago and also trying to win his national championship for the first time, 44-year-old Jimenez shot 67 to take over second place.
The round of the day, though, came from 20-year-old Yorkshire amateur Danny Willett, a 64 lifting him from 59th to 11th.
Nine under par for the first 14 holes, Willett needed only one more birdie to equal the lowest round by an amateur in European Tour history.
But as the television cameras arrived, he bogeyed the 15th and parred the remaining three.
Darren Clarke, winner of his first European Tour title for five years in Shanghai last week, finally shook off the jetlag with a 67 that put him eight under and in joint 14th place.
Colin Montgomerie, however, still looked rusty after his five-week lay-off – he married for a second time two weeks ago and then went on honeymoon to Venice - and with a 74 was only joint 66th of the 75 who survived the cut.
After leaving a 25-foot birdie putt on the 18th four feet short and missing the next one Garrido shrugged off the disappointment.
“It’s just one more hole in the round – nothing to worry about,” said the former Ryder Cup player, who teed off this week on the back of six missed cuts in his previous seven events.
“The rest of the round was good. I felt comfortable and am happy with my performance.
“I did hit a couple of not committed shots, but it just happens that you lose your concentration a bit.”
Garrido added that his most anxious moment, in fact, was when Tour senior referee Andy McFee approached him on the 16th hole.
“Of course it was slightly worrying – you never know what he is going to say.”
McFee had seen Garrido approach the caddie of playing partner Martin Erlandsson on an earlier hole and the caddie got out his yardage book.
Players are not allowed to seek advice, but all Garrido was doing was asking for the return of a pin placement sheet.
“It just looked odd at the time, but there was no penalty for what he did,” said McFee.
World number one amateur Willett, having made the halfway cut with nothing to spare, actually climbed to third place on his own early in the day when he produced an eagle and eight birdies in the first 14 holes.
He hit a tree on the next, however, and by also missing a seven-foot birdie chance at the 16th he fell one short of Garrido’s course record and two short of the amateur Tour record set by Sven Struver in the 1989 German Open.
“It was a bit disappointing, but there are some tough holes coming in,” said Willett, who on his Tour debut in March finished 19th in the Andalucian Open.
The clergyman’s son, winner of the English amateur title last year and a member of the Britain and Ireland Walker Cup side that so nearly beat the Americans, has already added the Spanish and Australian stroke play titles this season.
The first of those earned him a place in this week’s event and he added: “There’s a lot less pressure on me – I’m not playing for a mortgage.
“It’s good experience. I want to be out here with these boys at the end of the year.
“I was not thinking about a 59 (he would have had to birdie all the last four to be the first player ever to do that on the circuit). I was just trying to keep it going – I was on a really good roll.”
Willett’s next few months will be spent mostly back on the amateur circuit, but he will mix it with the pros again in trying to qualify for both the US Open and Open Championship.
Joint third on 11-under, four behind Garrido, are England’s Mark Foster, Dane Soren Hansen and Paraguayan Marco Ruiz.