John Catlin found himself in possession of a two shot lead with nine holes remaining on the final day of the Estrella Damm N.A. Andalucia Masters after his nearest challenger Martin Kaymer carded a double bogey on the ninth hole.
The pair had been neck and neck for much of the front nine, with former World Number One Kaymer carding two birdies and a single bogey in his first four holes to get to one under par, and American Catlin dropping a shot on the fifth to surrender the outright lead.
But following an errant tee shot on the ninth, where Kaymer lost his ball and had to hit a provisional, he made a double bogey six to fall to one over.
Just as it has done all week, the wind was causing problems again at Real Club Valderrama on Sunday afternoon but that did not seem to bother Kaymer in the early stages.
The German, who has said that one of his career ambitions is to win at this week's host venue, began the day two strokes behind Catlin but halved the deficit early on with a birdie from 12 feet at the second.
He gave the shot straight back after missing his par putt from the fringe at the short third but returned to the red numbers with a bounce back birdie from eight feet at the par five fourth.
Kaymer gave himself a good chance to pick up another shot at the fifth but just missed his birdie putt from 11 feet.
But when playing partner Catlin dropped his first shot of the day at the same hole moments later after his third shot from the rough only moved a little way forward, Kaymer found himself in a share of the lead on one under par.
Ryder Cup star Kaymer produced one of the best putts of the day on the sixth green, holing his par putt from around 25 feet after navigating his way out of a tricky spot in the bunker.
And with Catlin unable to roll in his birdie putt from ten feet on the same hole, Kaymer could breathe a sigh of relief.
Both players made good par saves on the seventh, with Kaymer doing well to find the green with his second shot after clipping branches off the tee and Catlin getting up and down from the rough.
It was Catlin's turn to get into tree trouble off the tee at the eighth but he was able to save par from eight feet, and he watched on as Kaymer missed his 25 foot birdie putt.
After a poor tee shot at the ninth led to Kaymer needing to hit a provisional, he dropped two shots to head to the turn two strokes behind Catlin, who was unable to convert his birdie putt from 12 feet.
Justin Harding was alone in third place on three over par after making two birdies and one bogey in his first ten holes.
