Andy Sullivan took advantage of excellent scoring conditions to record his second 63 of the season on day two of the Open de España.
A softened layout and preferred lies meant conditions were ripe for low scoring and Sullivan - who had started with a 75 on Thursday - went 12 shots lower with his nine under par effort.
German Marcel Schneider also signed for a 63 to sit a shot behind Sullivan at five under, as both men threatened the lowest ever round at the Open de España - a 61 from Wayne Riley in 1988.
Sullivan finished 62nd on last season's Race to Dubai Rankings presented by Rolex after making the top 15 the previous two years, but he has made all six cuts so far this term with a best finish of sixth in Dubai, where he fired a 63 in round three.
"I think the putter had just come out into the fire today," he said. "Yesterday I had a four-putt and a few three-putts out there and I knew I needed to get off to a quick start today.
I'm positioned nicely and hopefully it stays as it is and I can throw a couple of low ones in at the weekend - Andy Sullivan
"Parring the first par five I was thinking, 'Oh no you've put yourself behind the eight-ball' but the putter got warm on that back nine and I really started to get into it.
"Six under on the front nine was just what I needed really and I could just ease myself into the back nine and pick my chances when I had them. It all added up to 63, which was great.
"I birdied the last two holes last night so I think that gave me a little bit of optimism. I think five (over) would have been tough to make the cut but I holed two good putts on 17 and 18 last night which gave me a little bit of momentum this morning and I felt good about my game. I felt good about my game yesterday, I just putted awfully but today was a lot different.
"That's what I was going for on the back nine, I was thinking 'more birdies, more lie-in time' but I'm positioned nicely and hopefully it stays as it is and I can throw a couple of low ones in at the weekend."