Jorgensen, with mother Kathi caddying for him, beat Keith Hendrickson of Syosset, N.Y., 1-up in the second round and Brazil's Fernando Mechereffe 1-up in the third round.
Lubhan, in the lower bracket along with Jorgensen, routed Brett Jones of Paducah, Ky., 7 and 6, and Justin Walters of Raleigh, N.C., 7 and 5 in the rain-delayed third round.
Jorgensen, the North & South Amateur winner, will face Chris Stroud of Groves, Texas, in the quarterfinals at The Orchards Golf Club. Lubhan will play Ryan Moore of Puyallup, Wash.
In the upper bracket, Billy Zihala of Little Rock, Ark., will face Brady Stockton of San Ramon, Calif., and Lee Williamson of Crawfordsville, Ind., will play Wren Fowler of Thomson, Ga.
Fowler beat Burke Spensky of Huntington, W.Va., 3 and 2 in the third round after Spensky routed defending champion Chez Reavie of Phoenix 6 and 5 in the morning round.
The winner of the 36-hole final Saturday will receive an invitation to the 2003 Masters, as long as he remains an amateur. The tournament is open to amateurs who do not have regular playing privileges on a private course.