Minoza fired a brilliant 10-under-par 61, just one shot outside the lowest round ever recorded on the European Tour.

Darren Clarke was the most recent player to shoot a 60 in the European Open at the K Club in 1999, although Clarke's effort was on a par 72 course.

It gave the 41-year-old Minoza a halfway total of 125, 17-under-par, and the lowest sub-par total for the first 36 holes in the tour's 30-year history.

Ireland's Padraig Harrington remained in contention to gain revenge over Singh for his play-off defeat in Malaysia last week, shooting a 67 to finish 12 under and in third place alongside Thailand's Prayad Marksaeng.

England's Warren Bennett, joint leader overnight after an opening 63, carded a second round 69 to lie joint seventh on 10-under-par alongside Wales' Mark Mouland, one ahead of Colin Montgomerie.

"I cannot believe I shot 61," admitted Minoza who had just 10 putts in his inward half of 29. "I really like this course I guess. I first played it in 1975 as a junior and have won twice here and finished runner-up twice.

"Before I played last week in Malaysia (he finished 71st out of 73 to make the cut) I had not played for seven weeks and I hit the ball so badly. I don't know what happened here."

Minoza might have expected to enjoy more than just a two shot cushion after such a round but Singh, who celebrated his 38th birthday on Thursday, was lurking ominously just two shots behind and has yet to drop a shot this week.

Harrington somehow conjured up his 67 despite hitting only two fairways in regulation all day and making several excursions deep into the trees.

Montgomerie also recorded a 67 and was disappointed to fall so far behind the leaders after starting the day just three shots back, failing to take advantage of his early tee time.

"I had to get to 12 under really today and I'm not," said the 37-year-old Scot who won the Australian Masters last week. "I missed a couple of short putts and I'm stuck at nine unfortunately.

"But there is nothing wrong with my game and I've got a chance if I can shoot something low at the weekend, very low. Even if I don't score particularly low that's fine, I've had a good first two weeks out and I'm looking forward to Dubai and on to Bay Hill.

"I'll be in the last five or six groups which is where you want to be again. I started the last round last week five behind. Anything can happen. I'm hitting the ball well enough and if I hole some putts anything can happen. "

Bennett, who contemplated quitting the game last season after years of injury problems, also struggled to follow up his excellent first round score with four birdies and two bogeys in his 69.