Bob May added a second five-under-par 66 to grab a share of the lead with Steve Pate in the St Jude Cassic in Memphis, Tennessee, yesterday.
Pate followed his opening 67 with a superb 65 to join May on 132, 10 over par.
Bray's Keith Nolan failed to make yesterday's cut despite a second round 72. His opening 75 left him with too much work to do.
Ross Cochran (66) and Joe Ogilvie are in joint third, a shot behind the leaders.
Ogilvie is without a win in 47 events since joining the tour in 1999 and is trying to become the fifth first-time winner on tour this year.
Ogilvie changed his putting style last week, and it has paid off.
"I called my caddie during last week and told him I was making my putting change," said Ogilvie, who proclaimed himself the worst putter on tour before this week.
"Guess he said to his wife, `The guy is finally going to make some money'."
Meanwhile, Britain's Laura Davies moved into a two-shot halfway lead after a spectacular finish to her second-round 66 in the McDonald's LPGA Championship at Wilmington in Delaware, the second major of the women's season.
With birdies at the final three holes - including a lip-out for a hole-in-one with an eight-iron at the 156-yard 17th - Davies posted a six-under-par 136 total to move two clear of American Wendy Ward and three ahead of the rest.
A two-time former winner, Davies, seeking her fifth major, said: "This is definitely one of my favourite places and I played great today.
"I've been working a little harder on my game this year and it's definitely paying dividends. Not that I'll ever be a slave to the range."
In the glorious sunshine, Davies overpowered all three long holes - the ninth, 11th and 16th - while after the tap-in for two at the 17th she then holed from 15 feet for a birdie at the last.
"It's always nice to finish well and today was great. I love this course so much because I can use my driver," she explained.