Thorpe's 60 matches the tour record first set by Isao Aoki in 1997 and later matched by Walter Morgan and Bruce Fleisher. Thorpe's two-round total of 128 broke Fleisher's previous tournament record of 129, which he set in 2000. Fleisher had set the 18-hole record on Friday with an 8-under 62.
'I didn't hit a lot of balls on the range today, but spent a couple hours on the putting green,' said Thorpe. 'It paid off as my putter was on today.'
Bob Gilder stands alone in second place at 10-under-par 130. Des Smyth owns third place at 8-under-par 132, with Mike McCullough one stroke further back at minus-7.
Thorpe got rolling at Eisenhower Park's Red Course quickly on Saturday. After missing a short birdie try on the first, he rolled home a 40-foot birdie on the second.
He followed that with a four-foot birdie putt at the next and made it three straight when he sank a 10-footer on the fourth. The 54-year-old converted a six-footer on No. 6 for his fourth birdie of the day and capped his front side with a short birdie at the ninth.
On the back side, Thorpe missed a few good chances but also took advantage of several others. He two-putted for par on the 10th before sinking an 11-footer for birdie on the 11th. He made it two in a row with a birdie at the 12th and birdied the 13th to complete his second run of three straight birdies.
Standing at minus-10 for the event, Thorpe failed to convert three straight birdie tries from the 14th ranging from nine feet to 32 feet. He finished with back-to-back birdies to close out his magical round.
'I was patient out there today. I left three or four putts out there,' said Thorpe, who posted his personal best score by two strokes. 'I'm surprised the scores are so low. Our group played well and were making a lot of birdies. It kind of fires you up.'
Gilder stumbled out of the blocks with a bogey at the first. He came right back to birdie the next. He sank his next birdie at the par-3 fifth.
Around the turn, Gilder bogeyed the 10th for another poor start to his nine. He responded with back-to-back birdies from the 12th. The seven-time winner on the Champions Tour rolled in a 30-footer for birdie at the 15th and closed with a two-putt birdie at the 17th.
'Overall, I hit the ball well, but my driver let me down some,' said Gilder. 'I think I played a smart round and made some putts. I'm glad to be only two shots back the way Thorpe played.'
Fleisher, who held the overnight lead, stumbled to a 2-over 72. He stands at 6-under-par 134 in fifth place. Bobby Walzel, Vicente Fernandez, Mike Hill, Gary Koch, Wayne Levi and Rodger Davis are one stroke further back at minus-5.