Santos automatically advanced into the second round by virtue of his being the topseed in the boys 16-under. He also drew a bye in the boys 18-under.
Cansino, who won in the Lilo-an leg recently, also marched outright into the next round in the boys 12 and 14-under categories.
Together with Cansinco taking a bye in the boys 12-under is Kim Ayuda and Ralf Sobrevega in the 14-under.
With Santos taking a bye in the 16-under are Larry Antigua, Francis Largo, and Gerard Pinili.
Antigua also enjoyed a bye in the 18-under together with Santos, Mark Joseph Sierra and Joelrico Pagsiat.
At the start of hostilities in the 140under, Kurt Campo defeated Gideon Huyo-a, 6-1, 6-1, Carlo Ledesma outsmarted Gabriel Ortiz, 6-3, 6-1 and Michael Aguinar outplayed Aaron Espina, 6-1, 6-3.
In the 16-under, Lowell Lloyd Cañete dumped John Patrick Aba, 6-1, 6-1, while April Joy Ledesma pulled a hard-earned win against Louie Alcomendra, 7-6, 6-3. Ryan Montalbo got a 7-5, 6-2 victory against Ralph Sobrevega.
Gerald Lambayan slammed Richard Guror 6-1, 7-6, Ronard Macalos zapped Dudes Flores, 6-1, 6-0 and Jade Labaya whacked Amiel Aya-ay, 6-2, 6-2.
The boys 18 division saw Romelito Villamor clobbering Ryan Ocio, 6-0, 6-1 and Larry Antigua whipping Ryan Montalbo, 6-3, 6-2.