John E. Morgan, who lost a playoff last week that cost him a chance to play in the British Open, shot a 4-under 68 and is tied for second with Daniel Chopra, who carded a 65. The duo is knotted at 11-under-par 133.
Todd Fischer (69), Chris Smith (65), Roland Thatcher (68) and Neal Lancaster (67) share fourth place at minus-10.
Byrd opened on the back nine Friday and rolled home a 25-foot birdie putt at his first hole. He tallied back-to-back birdies from the 12th, but found trouble at 15. Byrd's approach plugged in a bunker and he left with a bogey.
The 2002 Buick Challenge winner once again reeled off two birdies in a row, this time from the 16th and opened his second nine with a 15-footer for birdie.
Byrd got up-and-down for birdie from behind the green at the par-5 third. He took sole possession of the lead with a 15-foot birdie putt at the sixth, but trouble loomed.
He three-putted for bogey at the par-3 seventh, but once again got up-and-down for birdie from behind the green, this time at the eighth. That birdie gave Byrd the lead at the 36-hole mark for the first time in his PGA Tour career.
Byrd has struggled so far this year, but he has a good excuse. He had hip surgery in February to repair two tears and the return has been a slow process.
'My swing got better from surgery,' said Byrd. 'I was sliding in my backswing. The year has been a struggle. I've felt good the last few weeks. I'm a better player than last year.'
Morgan did not look like he would pick up his first birdie when he did. He missed the green at the par-5 fifth and duffed his first chip. Morgan then chipped-in for a birdie to get into red figures.
The young Englishman tallied a tap-in birdie at the ninth and ran home an 8-foot birdie putt at the 12th. Morgan went for the green off the tee at the 321-yard, par-4 16th. He came up short, but chipped on and made the birdie putt to polish off his bogey-free round.
Morgan lost a playoff to Mark Hensby last week at the John Deere Classic. He mistakenly thought that gave him an spot in the field for the British Open because Hensby turned down the invitation.
The spot did not fall to Morgan after Hensby passed, but Morgan is continuing his strong play.
'Something has been brewing for a couple of months,' said Morgan. 'Something is clicking and we'll see what happens. I'm very patient out there and staying with the game plan.'
Chopra began on the back nine and knocked a 7-iron to 12 feet to set up birdie at the 12th. He nearly holed his tee ball at 17, but settled for a tap-in par. Chopra hit a sand-wedge to three feet for a birdie at No. 18 to make the turn at 3-under 32.
Chopra, a two-time winner on the Nationwide Tour this season, missed a pair of birdie putts inside 10 feet at the opening two holes of his back nine. He two-putted from 45 feet for birdie at the par-5 third, then rolled in a 3-footer for eagle at the par-5 fifth.
He took advantage of the third par-5 on the front side at En-Joie. Chopra reached the front edge of the green with his second, then chipped on and made birdie.
'I saw the course for the first time on Thursday,' said Chopra. 'It was a lot calmer conditions today. I played well yesterday too, it was just tougher conditions.'
Notah Begay III fired a 10-under 62 on Friday and is part of a large group tied for eighth at 9-under-par 135. Kevin Stadler, a two-time winner so far on the Nationwide Tour this year, is also at minus-9 after a second-round 70.
Kevin's father Craig Stadler, who is the defending champion, shot a 3-under 69 and is tied for 16th at minus-8. Robert Gamez matched the course record Friday with an 11-under 61 and is part of the group four shots behind Byrd.
The 36-hole cut fell at 2-under-par 142 and Fred Funk, who passed on a spot in the British Open to play this week, made the cut on the number.