Michael Hoey birdied two of his final three holes but his two under par total that was not enough to make the cut, missing by one shot.
The event ambassador hit a double bogey on his twelfth hole and finished 10 shots behind leader Emilio Cuartero Blanco.
It's the third year in a row Hoey has failed to make the cut in the event.
Blanco shot a second successive round of 65 at Galgorm Castle to lead by one shot on 12 under par at the halfway point of the Northern Ireland Open in Association with Sphere Global and Ulster Bank.
The 24 year old, bidding to become Spain’s third European Challenge Tour winner this season after Nacho Elvira and Borja Virto Astudillo, did not drop a shot all day while adding six birdies to the eight made in his opening round and leads from John Hahn and leading Irishman Niall Turner.
Cuartero Blanco’s previous best finish this season was a tie for ninth in the curtain-raising Barclays Kenya Open but he has quickly found his best form in front of the Northern Irish crowds at one of the best-attended events on the Challenge Tour.
“I played really solid golf again today,” he said. “I didn’t make any mistakes like the two bogeys I had yesterday, and I can’t really complain about anything. I felt strong mentally and played really well for the second day running, so I’m very happy.
“I’m hitting good fairway shots and then off the tee I’m just staying out of trouble, because on this course you can find trouble at any time.
“But I’m especially happy with my mental game. I’m really focused on every shot, I don’t have birdies in my head, it’s just clear and it’s helping me play good golf.
A local player told me 'this is Northern Ireland's only day of summer, so you'd better enjoy it!'
“I got a tip from Nacho on Wednesday afternoon when I was practising my putting. He told me my putting stroke looked really fast and that I should slow it down a little bit and after that I hit through the line better, better speed on my putts as well, so thank you Nacho!
“Conditions were perfect today. I was playing with Gary Wardlow, a local player, and I asked him how many days of summer do they get like this one, and he said ‘one, so you’d better enjoy it!’ I don’t think we could play this course in better conditions really, it’s perfect.
“We’ve only done two days and actually now, we have the hard work to come. I just need to enjoy the course, try to play well, and then on Sunday we will see.”
Hahn, co-leader after round one, needs a good finish to boost his Road to Oman Ranking, where he currently sits in 77th after just one top five finish this season, at the D+D REAL Czech Challenge.
The 26 year old American came through Qualifying School in 2013 to earn a place on The European Tour but insists he is not looking too far ahead at this point, despite his great start here.
“I’m just trying to have fun,” he said. “I wasn’t doing that for a while but I’m just trying to enjoy myself on the golf course now.
“I’ve got no expectations or goals on myself for this week, my only goal would be to maybe get in contention and see how I deal with that.
“My pairing for the first two days, with James Heath and Ross McGowan, was perfect, I’m quite chatty on the course and they made me really comfortable.
“Momentum is a big thing here and I carried some into today so hopefully I can keep that going through the weekend.”
Turner has only recently returned from a long-term back injury but has found form in front of the Irish crowds and is keen to make up for lost time.
“I’ve had a long time waiting to get back out here,” he said. “It’s been a complete nightmare to be honest so to be back now and in contention is fantastic, I couldn’t have wished for anything more.”
One shot further back are Scotland’s Jamie McLeary (pictured above), third here in 2013 and now 21 under par for his last four rounds at Galgorm Castle, and Frenchman Sebastien Gros, currently second in the Road to Oman Rankings.
Daan Huizing (pictured below), another of the co-leaders after the first round and winner of this event in 2013, is well within striking distance on nine under par alongside Australian Scott Arnold.
Northern Ireland’s own Gareth Shaw gave the home fans something to cheer about by firing the low round of the week so far, a seven under par 64 helping him to make the cut after a shaky opening round of 73.
Chris Selfridge trumped Shaw to be the leading Northern Irishman heading into the weekend after the 23 year old carded a five under 66 to sit four off the pace on eight under.
Tournament Ambassador Michael Hoey birdied two of his final three holes but his two under par total that was not enough to make the cut, missing by one shot.