Pavin, one day removed from establishing a new PGA TOUR record for best nine-hole score when he went through the front nine in 26, is 3 under par through 11 holes of his second round.
Jeff Sluman, a two-time former champion, carded a second-round, 5-under 65. He is tied for third place with D.J. Trahan (65), native son Jerry Kelly (67) and Australian Nathan Green (64). The group is knotted at 9-under-par 131.
Arjun Atwal is 3 under through 11 holes of his second round.
A lot of golf was played at the Brown Deer Park Golf Club on Friday in an effort to get the tournament back on schedule. Thursday's action featured a five-hour weather delay before play was suspended for the day.
With most of the field yet to complete the first round, they returned early Friday morning. Most of the group that did not tee off on Thursday played all 36 holes on Friday in 90-degree temperatures.
The second round was not completed on Friday, so golfers will be back in position Saturday morning at 8:00 a.m. (ET). The plan is to begin the third round around 11:00 a.m. in threesomes off both the first and 10th tees.
Pavin, who won this title in 1986, started on the back nine in round two and parred his first four holes. He broke into red figures for the first time with a 4-foot birdie putt at the 14th.
On the next hole, the par-5 15th, Pavin left himself with 6 feet for birdie and he converted the putt to join Bohn atop the leaderboard at minus-11.
On Thursday, Pavin needed an eagle at the par-5 final hole to shoot 59, but only made par. He admitted that he went for the green in two when he shouldn't have, but laid up on Friday and made birdie to take the outright lead.
Pavin played solidly on his last two holes, but could not collect any additional birdies. When the horn sounded, he was one ahead with 25 holes on the docket for Saturday.
Bohn, who did not play in last week's British Open even though he was qualified because he wanted to defend his B.C. Open title, parred his first four holes in the second round, but collected back-to-back birdies from the fifth.
The 36-year-old bogeyed the eighth hole to fall back to minus-6, but reclaimed the lost stroke with a birdie one hole later. Bohn birdied the par-3 11th to reach 8 under par for the championship.
Bohn tied for the lead at the par-4 14th when his wedge approach stopped 7 feet from the hole to set up birdie. It was his play down the stretch that got Bohn near the top of the leaderboard.
At the par-4 17th, Bohn drained a 6-foot birdie putt to move into the lead by himself at 10 under par. He came up short with his second shot at the par-5 closing hole, but chipped to 4 feet and converted the birdie opportunity.
Bohn played one hole on Thursday before the horn sounded. That meant Bohn played 35 holes on Friday in 11 under par and considering the conditions, that was an impressive feat.
'It was pretty tough. I knew it was going to be a hot day and a struggle,' said Bohn, who will extend the fourth longest consecutive cuts made streak on tour to 14. 'I kept telling my caddy that if we kept making birdies, that will keep pumping you up.'
Jason Day, who turned professional less than two weeks ago, shot a 6-under 64 in the second round. He is the only player in the clubhouse at 8-under-par 132.
Former PGA Champion Shaun Micheel is at minus-8 on his second nine.
One player who will definitely not be around once the 36-hole cut is made on Saturday is 2005 winner Ben Crane. He was disqualified on Friday for signing an incorrect scorecard.