John Catlin heads into the weekend with a two shot lead at the Estrella Damm N.A. Andalucia Masters after producing a late birdie burst on day two.
The 29-year-old made back to back gains at the 16th and 17th to move to three under par and become the only player to break par in both rounds this week, following up Thursday's 69 with a 70 that contained four birdies and three bogeys.
Playing in the final group on Friday afternoon, overnight co-leader Catlin had remained at the summit for most of the day as blustery conditions caused havoc at Real Club Valderrama once again.
A lightning fast start to his second round saw the American stretch his lead, as birdies at the first and third took him to four under par. But he dropped three shots in his next seven holes to surrender the outright lead and join Pablo Larrazábal, Connor Syme and Jamie Donaldson - who had already finished their rounds - on one under.
Catlin regained the initiative with a birdie at the 16th before picking up another shot on the par five 17th to establish a two shot cushion at the halfway stage.
Spaniard Larrazábal, Scotland's Syme and Welshman Donaldson were the only other players under par, in a tie for second.
Catlin, who has yet to taste victory on the European Tour but has four Asian Tour wins to his name, was pleased with his ability to hang in there on another difficult day in southern Spain.
He said: "I was hanging on in the middle of the round. I got off to a hot start again but then I started making bogeys, which you can do out here pretty easily if you miss a fairway here and a green there.
"I made a really good bogey on the ninth, that could have been a double pretty quickly. I hung in there all day and was able to hole putts there on the 16th, 17th and 18th.
"I hit a great shot on the 18th, I just misjudged the wind a little bit. It’s nice to get two good ones in over the first two days.
"Winning is never easy. It doesn’t matter what Tour you’re on, you have to go out there, make birdies and hole putts.
"Being able to look myself in the mirror and know I’ve done this before and can do it again is hugely helpful. It helped me out there today, even though I haven’t won a European Tour event, I know I’m fully capable of doing that."
Home favourite Larrazábal came into the week hoping to recreate some of the fine golf he has produced on this course over the years and get his season back on track, having struggled for form since the European Tour returned following the four month hiatus.
And he did just that on day two, making four birdies, three bogeys and some wonderful par saves in his battling 70.
Having fired birdies at the third and fourth to jump to two under, Larrazábal dropped his first shot of the day on the seventh but made amends with a six foot birdie putt at the 11th before getting a lucky break on the 12th when his tee shot hit a tree and got a favourable bounce.
The five time European Tour winner went on to get up and down for par there before producing a superb wedge shot and rolling in for a birdie at the next to move to three under.
Larrazábal did well to drop just the one shot at the 14th after chipping out from under a tree, and he followed that up with a perfect bunker shot to save par on the tricky 15th.
After three putting for a par on the 17th green, Larrazábal bogeyed the last but will take a lot of confidence from the fighting spirit he showed on day two.
"I'm grinding well," said Larrazábal. "I didn't play my best golf today.
"I played very poorly in the UK Swing, and I didn't play any good today, but I hung in there, making pars.
"I hit a couple of great shots - the third on the 11th and the second shot on the 13th.
"I'm happy with the fight, with the mental work I've been doing the last couple of days, and I’m happy for the result."
Morning starter Donaldson had set the early clubhouse target on Friday after producing a brilliant burst of scoring around the turn to sign for a 69.
Donaldson said: "I’m very pleased. It’s a battle out there on the best of days, even when there’s no wind blowing here it’s still difficult.
"It was blowing 30 yesterday and probably 20 today. It’s very difficult, you’ve got to be very patient out there. I’m happy with the position I’m in."
Syme began the day in a four way tie for the lead on two under and found himself back at that mark after a topsy turvy start to his round that saw him card three birdies and three bogeys in his first 11 holes.
Further bogeys at the 13th and 15th could have derailed Syme's challenge but he bounced back with a 12 foot birdie on the 16th before saving par from range on the 17th on his way to a 72.
"I'm happy with the way I grinded," said Syme. "And I holed a few nice putts there at the end to salvage a pretty good score again today."