At 11-under-par, Thorpe and Patino are one shot clear of Bruce Summerhays and Hugh Baiocchi. Gary McCord, Jose Maria Canizares, David Graham, John Mahaffey and Jim Colbert are all two back at 9-under-par.
Patino, who shared the 18-hole lead with Baiocchi, Mahaffey and Colbert, parred his first eight holes in the second round, before birdying the par-5 9th. Patino added a second straight birdie at the 10th, and then carded three more on the inward half for a round of 5-under-par 67.
Thorpe also posted a one-birdie, eight-par front-nine 35. He then proceeded to birdie five of the nine holes on the back for a round of 66.
Summerhays held the outright lead at 12-under through 16 holes, but bogeyed the 17th and 18th to go from one up to one down. Baiocchi, likewise, found trouble at the 17th, carding a double bogey 5. But the three-time Senior Tour winner birdied the home hole to grab a share of third place with Summerhays.