John Catlin will take a two stroke lead into the final round of the Estrella Damm N.A. Andalucia Masters after his patient approach paid dividends on another windy day at Real Club Valderrama.
Catlin is used to being in the winner's circle, having claimed four Asian Tour titles, but he has yet to taste victory on the European Tour and will be looking to do just that on day four.
The American produced an outstanding display of front running on Saturday and found himself five clear at one stage after holing his 35 foot birdie putt at the 14th.
And despite finishing with back to back bogeys to sign for a 72, Catlin was the only man under par ahead of Sunday's final round.
Two time Major Champion Martin Kaymer was Catlin's nearest competitor on level par after carding three birdies and a solitary bogey in a stunning 69.
Ryder Cup star Jamie Donaldson and Lorenzo Gagli, who made a hole-in-one from 203 yards on the short 12th, were another shot back in a tie for third.
Catlin began the day with a two shot lead and did not put a foot wrong over the first nine holes at Valderrama, keeping his card clean with seven straight pars before a birdie from 12 feet on the eighth took him to four under par.
After sending his tee shot at the par five 11th a long way left, Catlin dropped his first shot of the day after narrowly missing his 25 foot par putt.
The 29-year-old held his nerve with a sensational up-and-down after missing the green at the 12th to avoid putting another bogey on his card, before draining a monster birdie putt on the 14th green to return to four under and open up a huge lead.
But after making a solid par save at the 16th, Catlin found the water on the 17th and surrendered a bogey there after failing to get up and down from a bunker.
He let another shot go at the last after getting into more trouble off the tee but remains in a healthy position with 18 holes to play.
Catlin is looking forward to doing battle with Kaymer on Sunday.
He said: "The mental side is very important – you’re going to hit good shots and not end up in good spots and you’re going to need to be able to bounce back, keep your mental focus in the right place.
"That can be tough, but I’m proud of what I was able to do from that side of things and I’m looking forward to tomorrow.
"It’s very difficult to win, it doesn’t matter what Tour you’re on. Having that winning experience gives me a lot of confidence so I’m going to go out, give it my all and see where everything lands.
"It’s going to be a fun day. Martin’s a very good player and I look forward to seeing what he does, but I wouldn’t be in that group if I couldn’t compete also so I’m looking forward to seeing what I can do too."
Kaymer, who lists Valderrama among his top three courses in the world, came into the day five shots behind Catlin after posting successive 72s on Thursday and Friday.
But he made a good start, notching birdies at the first and fifth before dropping his only shot of the day at the seventh.
The German then rolled in from around six feet for another birdie at the par five 17th before getting up and down from a bunker for par at the 18th to finish the day two shots behind Catlin.
Ahead of the tournament, Kaymer said winning here had been a long held ambition, and he is hoping to realise that dream on Sunday.
"Winning in Valderrama was always one of my goals, one of my dreams," he said. "The first time I came here in 2007, I pulled the cart myself in my practice round and that was one of the most enjoyable practice rounds I’ve ever had because it was just you and Valderrama.
"To win here would be something very special."
Gagli hailed the "perfect shot" after making an ace in his third round 71 that contained an eagle, two birdies, two bogeys and a double bogey.
He said: "It was a perfect shot, four iron. The wind was into from the left. I hit a perfect shot, a little low with a little draw and it landed just at the front of the green and rolled in. I think it’s my first."
