Welshman Jamie Donaldson, without a win in the 244 European Tour events he has played, takes a one-stroke lead over England's Anthony Wall, without a win in his last 364, into today's final round of the Irish Open at Royal Portrush.

The pair have the same aim, but have taken a different approach to the week. Donaldson is staying in a boutique hotel which the local tourist board says "sets a new standard" for the area. Wall is in a caravan.

"It's quite a posh caravan – it's got running water, it's got gas," said the 37-year-old Londoner, after battling wind and heavy rain for a brilliant five-under-par 67 he described as "probably the best round I've ever played".

Wall is sharing with fellow player Andrew Marshall and explained: "I didn't want to stay in town because it was going to be quite boisterous. I knew we would have a bit of fun and it's been nice to relax."

With overnight leader Gregory Bourdy crashing to an 80 – including a triple-bogey eight on the 17th – Donaldson took over at the top with a 69 for a 12-under total of 204. Three-time Major winner Padraig Harrington, though, is still title favourite. The 2007 champion's 72 left him sharing third spot with Englishman Mark Foster, two behind, while Rory McIlroy is six back, Graeme McDowell eight behind and Open champion Darren Clarke nine adrift.

Scotland's Lee Craig was tied sixth on eight under after a 67, and countryman David Drysdale was joint 11th after a 70 took him to six under.

Donaldson has had 32 top-10 finishes in his Tour career, but hopes his first hole-in-one on the opening day can help him to victory.

"I've had a few chances, but at the end of the day I've not been good enough so far to stand on the last green holding the trophy," said the 36-year-old. "You've got to keep trying and it's one shot at a time, one hole at a time.

"The only person I am playing against, I suppose, is myself. I've got to stay out of my own way.Obviously Padraig is a class player, but it's me versus me really."

First prize is over £267,000 and the title would mean the world to Donaldson. After an opening bogey he eagled the long second from 10 feet, saved par from 20 feet at the fourth, then made birdie putts of 10ft and 25ft on the next two greens. With conditions really tough – there was still a crowd of more than 30,000 for the first Irish Open north of the border since 1953 – Wall caught him, but Donaldson edged back in front with another birdie at the 16th.

Wall had birdied three of the first four holes and then on the long ninth into the wind struck "the best drive and 3-wood I've ever hit".

He found the elevated green, two-putted to turn in 32 and after running up a six on the 478-yard next added further birdies at the 11th and 17th. There was a real danger the last might spoil his day when his drive bounced off a spectator into a bush.

But after taking a penalty drop his 7-iron third shot finished just six inches from the flag and he escaped with a par.

Harrington said: "You might think I am the form card, but we are all going to have our little demons out there."