Peter Lawrie must bridge a nine-stroke gap on home favourite Ignacio Garrido at the Spanish Open in Seville.
The Dubliner, 33, is tied for 13th on six under par after a 70 and three ahead of a jet-lagged Darren Clarke, who shot 69.
Paul McGinley birdied his final two holes for an impressive 68 as Gary Murphy and Gareth Maybin missed the cut.
But the man they all have to catch is Spaniard Garrido, who hailed his nine under par course record 63 as “the best golf of my life”.
Garrido carded nine birdies, slicing two shots off the day old record of overnight leader Martin Erlandsson of Sweden, who had opened with a 65.
Erlandsson is in second place on 11 under par, after a second round 68 which featured an eagle three at the fifth hole.
But the Swede is still four shots behind Garrido, who is seeking his first European Tour title since his triumph at the BMW PGA Championship in 2003.
Garrido said: “That was probably the best golf of my life – I played perfectly, and had lots of fun out there. We play a very tough sport, so it’s important to enjoy the good days. It can go fantastically well one day then not so great the next, so I’m not getting carried away.
“I’m just going to keep plugging away, and keep faith in my abilities. I’ve felt really comfortable on the range this week, and fortunately I’ve been able to take that form into the tournament.
“This is a great golf course but it’s also very demanding – you can’t afford to lose concentration for a minute. I haven’t visited the rough too often, otherwise I wouldn’t be in this position. The mental side of my game has been good.
“It’s a dream to play so well in front of my home fans at my national Open. I finished runner up in 1995 and 1999, but have never won. Other than the Majors, this is the one tournament all Spaniards want to win. I’ve given myself a great chance, but there’s still a long way to go.”
Garrido’s morning exploits put the pressure firmly on Erlandsson to maintain his recent form, and the Swede duly obliged with another sub-70 round which extended his streak of consecutive cuts made to 11 – a European Tour record.
The Swede said: “Obviously Ignacio’s round put the pressure on me, but I also saw it as a good opportunity to post a low score round here. I was probably a bit tense on the first few holes, but I decided to go back to basics and relax more, and it did the trick.
“I feel really good about my chances. I enjoy getting in positions to win tournaments and testing myself. I can feel my game coming together, and hopefully a win is just round the corner. I’m looking forward to playing in front of the fans with Ignacio tomorrow – it should be a good atmosphere.”
Garrido’s compatriot Carlos Rodiles, who carded his second consecutive round of 68, is also in contention on eight under par, along with Australia's Peter Fowler and Paraguay's Marco Ruiz.
Earlier in the day, England’s David Lynn shot a flawless round of 66 which also saw him move to eight under par, one shot clear of compatriot Mark Foster and the Spanish pairing of Miguel Angel Jiménez and José Manuel Lara.
Jiménez started slowly with a bogey on his third hole, but his round sparked into life with five birdies after the turn.
The Spaniard, who started on the tenth hole, said: “I hit a beautiful second shot onto the 18th green to set up a birdie chance, and that really got my round going. I needed a kick to give me some confidence and put a string of birdies together.
“The Spanish Open is obviously a tournament I would love to win at least once in my career. Seville’s a lovely city, and the fans have been very supportive. The course is in amazing condition from tee to green. I’m really looking forward to the weekend now.”
Tired after his win in the BMW Asian Open last week, Clarke comfortably made the cut after a second round 69 saw him finish day two on three under par.
He said: “I slept better last night, and felt much better today. I had some great chances but made a few mistakes, but I’m trying. I’m a long way behind the leaders, but I won’t give up. A couple of good rounds over the weekend will give me a chance.”