De Castro will meet Art Thomas Calingasan, an 8-7 winner over Michael Mantua while De Guzman will face Edu Manzano, who beat Reynaldo Laroya, 8-7.
In other matches, Jovan Divinagracia trounced Noel Mendoza, 8-6, to advance against Edward Larriosa, an 8-2 winner over John Amita while Menandro Econg outclassed Renato Tarroza, 8-1 to advance against John Sabado, an 8-2 winner over Danilo Olosin.
Numero Lim, Jerry Nicol, Maclean Barraquias, Irvin Nicolas and Aguel Buday also earned second-round berths in this event presented by Dunlop and Accel with support from Chowking, Photokina, PBCom, San Miguel Corporation, Coca-Cola, PVL Restaurant-Little Lawrence, Tobys, Copacabana, Trans Asia and The Philippine STAR.
Lim clobbered Gino Bautista, 8-3, Nicol whipped JV Cruz, 8-2, Barraquias won over Sidney Mella, 5-0 (ret), Nicolas conquered Marvin Espina, 8-6, and Buday outplayed Dennis Perida, 8-2. In an afternoon encounter, Kyle Dandan survived a tough Joey Escobido, 8-6.
Eight qualifiers will advance in the 64-man main draw which will start on Saturday (Nov. 16). The mens singles champion will get P80,000 while the runner-up will receive P40,000. Other winners will earn P30,000 (womens singles), P18,000 (mens doubles) and P8,000 (womens doubles).