The older Tiu, Clarence, a former national training pool member, wiped out 1,326 pins in six games or an average of 221 pinfalls per game to top the collegiate boys division.
It was a clean sweep by the USC as Tiu's teammates Earl Benedict and Rafael Veloso knocked down 1,169 and 1,048 pinfalls to settle for second and third place, respectively.
The boys major class was also an all-USC show with Clark at the helm by scoring 923 pinfalls in five-game series. Johnson Tan wound up second with 870 pinfalls.
On the other hand, Elaine Uy delivered USC's third gold by toppling 1,136 pinfalls to outclass the Lim sisters, Jacklyn and Michelle of Velez College, in the collegiate girls category. Jacklyn took the second place honors with 1,119 pinfalls, while Michael landed at third with 1,077.
Jennifer Tan made up for Velez College by grabbing the girls majors division tiara with 850 pinfalls. Rocci Damole of St. Theresa's College finished second with 840 pinfalls, while Nikki Tan of Cebu Doctors' University clinched third place with 815 pins.
Sacred Heart School-Jesuit swept the boys juniors with Jomar Jumapao scoring 1,052 pinfalls for the gold and Jake Yap and John Gasataya posting 1,027 and 910 pins for the silver and bronze.
Alexis Sy of Philippine Christian Gospel School downed 948 pins to claim the girls juniors title as Sacred Heart School for Girls' Kimberly Lao and Germaine Uang logged in 978 and 859 pins to occupy the second and third spots.
Cebu Cherish School's Jefferson Tan amassed 542 points to dominate the boys bantam division, while John Vincent Galindo of St. Louis School and Jed Robert Joven of Marie Ernestine posted 503 and 486 pinfalls to land at second and third.
In the distaff side, Micah Co of Cebu International Education accumulated 557 pinfalls to seize the crown, while Xyra Cabusas of USC and Kimberly Mae Panuncillo of SHS-J registered 511 and 442 pins for the silver and bronze.