Tony Johnstone, Craig Hailine and John McHenry tied for the lead after two rounds of the Irish Open on Friday.
First-round leader Colin Montgomerie shot a 3-over-par 74 after injuring an ankle when he tripped while signing autographs before he played. Montgomerie had a 139 total and was one stroke behind the leaders when the round ended.Johnstone fired a 4-under-par 67 in the second round, while Hainline and McHenry had 68s.
Montgomerie declined suggestions he should withdraw after his mishap.
"I did it signing autographs," said Montgomerie. "I was doing them on the walk because otherwise I'd be there all day, but I tripped over a stone and tore a ligament."
These are three crucial weeks for the Scot, with Loch Lomond next week and the British Open after that, where he will be trying for his first win in a major.
"It was all right for nine holes, but then it started to get very sore and I lost my balance," he said, explaining a drive on 11 that hit a tree and went only 120 yards, a bogey at 13 and then a triple bogey two holes later.
"I'm only one behind here and I'm still possibly (the) favorite," he said. "In my own eyes I am."
Ernie Els recovered from two early double bogeys for a second straight 71 and was even with par after 36 holes. Nick Faldo and Ian Woosnam just survived the halfway cut, both at 5-over 147.