Glasson had a 9-under 135 total at Shoal Creek, and has made only one bogey - Friday on No. 16 - in the first 36 holes. Cochran had a 68.
Dan Forsman, tied for the first-round lead with Glasson, had a 73 to drop four shots back.
Glasson is seeking his first victory since winning the 1997 Las Vegas Invitational for the last of his seven PGA Tour titles.
Glasson, who underwent the last of 25 surgeries late in 2009, hadn't had the solo lead after 36 holes since the 1994 Tour Championship when he wound up tying for fourth.
His play has been steady and without costly mistakes through two rounds.
Glasson didn't miss any fairways Friday, went the first 33 holes without a bogey and took a four-stroke lead with his final birdie on 14. Then came the lone bogey two holes later. Glasson sounded almost relieved 'to get that out of the way.'
'I made one decent putt for par earlier on 13, and up to then I wasn't really challenged too much over the couple of days,' Glasson said. 'You're going to make bogeys on this course. Maybe somebody's gone two rounds without making one, but that's pretty impressive if they have.
'Sometimes it frees you up a little bit.'
He does have an anecdote to back that up. Glasson recalled his first win, the 1985 Kemper Open, when a bogey on the penultimate hole 'allowed me to play 18 without puking all over myself.'
This time, he said firmer greens contributed to his misfires on 13 and 16.
'The ball landed about pin high and released over the back' on 16,' Glasson said. 'The same thing happened on 13.'
Cochran, the 2011 Senior British Open winner, had birdies on 15 and 16 to break out of a pack in second place. He was sidelined for two months this time last year with a wrist injury, missing the Regions Tradition.
He had played Shoal Creek a few times before in the 1984 and 1990 PGA Championship and in a Southeastern Conference championship with Kentucky in 1978, the year after it opened.
'This just brings back great memories for me,' Cochran said.
He made a 15-footer on No. 16 for his final birdie.
'When I went through, the guy said there had been only three birdies, so very difficult hole,' Cochran said.
Funk overcame bogeys on the first two holes - both par 4s.
The 2005 Players Championship winner birdied Nos. 14 and 17 and saved par with a nice up and down from the rough on the final hole.
'I really saved the round the last five holes,' said Funk, who missed the cut at the Senior PGA two weeks ago. 'I was real pleased with that. I would rather start bad and finish good than the other way around.
'I held it together and kept myself in the tournament just at those last five holes.'
Funk had won the Tradition in 2008 and 2010 at Sunriver in Oregon.
Forsman three-putted the 18th hole for his third bogey of the final six holes and fourth overall. He had only one on Thursday.
'Today wasn't quite as enjoyable,' he said. 'That's the way Shoal Creek is, it giveth and it taketh away.'
He said he made a poor club choice on the 18th hole given the swirling wind.
'It was a little bit tricky out there,' Forsman said. 'I hit the wrong club and it was too far into the green. I misjudged the putt pretty bad. To walk out of there with a three-putt is pretty discouraging.'