Quinney stands at 15-under-par 129. His 36-hole total of 129 smashed the old record of 134, which Erik Compton set en route to his win here in 2004. Chris Wall shot 63 in 2004 for the old course record.
'I was hoping it was good enough,' said Quinney of setting a new course mark. 'It was just one of those days. There wasn't a whole lot of stress. To be honest, it could have been a really special day. Shooting 59 wasn't out of the question, but I'm not going to complain.'
Matt Hansen matched the old course record of 63 to climb into a share of second place at 14-under-par 130. He was joined there by Ron Harvey Jr. (65). Compton and John Mallinger are one stroke further back at minus-13.
Quinney got going with a birdie on the second, then converted back-to-back birdies from the fourth at Brookside Country Club. He moved to nine-under with a birdie on the par-three eighth.
The 2000 U.S. Amateur champion really caught fire on the back nine. Quinney birdied the 10th for the second straight day, that moved him to 10-under. He then birdied the 12th and 13th, each for the second round in a row.
Quinney stumbled to his only bogey at the par-three 14th, where he three- putted. He quickly atoned for that error with a birdie on 15 to get back to minus-12.
The former Arizona State standout birdied 16 and 17 to get to 14-under. At the par-five closing hole, Quinney sank his second birdie in two days on that hole to close at 15-under.
'It never gets old. I mean, 15-under is 15-under no matter where you are playing,' Quinney said. 'You still have to get the ball in the hole. I'll need to keep it going on the weekend.'
Darren Griff posted a six-under 66 to move to 11-under-par 133. He shares sixth place with Scott Gibson and Dan Swanson. Brad Fritsch and Rob Johnson each shot 66 and are tied for ninth at minus-10.
Brian Guetz, who shared the lead after round one with Compton, managed only a one-under 71 and stands in a tie for 11th at 9-under-par 135. Defending champion Jim Seki is one stroke further back at minus-eight.
The cut line fell at 4-under-par 140, which tied the tour record for lowest 36-hole cut. Sixty-seven players moved on to the weekend.