The second-ranked De Guzman scored a 6-4, 4-6, 6-4 upset win over top seed Joseph Arcilla to capture his eighth boys’ 18-under title this year.
Villarete, the boys’ 14-under second seed, also pulled off a 6-3, 6-2 reversal over top seed Christian Canlas to pocket the crown.
Second seed Nestor Celestino Jr. bagged the boys’ 16-under title following a 7-6 (3), 6-3 victory over third seed Junjie Soquino.
Top seed Gerard Michael Ngo of Lourdes School rallied past second seed Joshua Tan Ho of Xavier, 1-6, 6-4, 7-5, to clinch the boys’ 12-under title while No. 1 Bernardine Siso downed fourth seed Joseph Baldonado, 6-3, 6-4, to win the unisex 10-under title.
In the girls division, Alyssa Labay of La Carlota, Negros Occidental was crowned 18-under and 16-under champion.
Labay, seeded fourth, won the 18-under title over top seed Bien Zoleta, 6-3, 6-4, and later annexed the 16-under title after posting a 6-2, 6-3 victory over Catherine Flores.
Unranked Michelle Pang won the girls’ 14-under title over fourth seed Melissa Orteza, 6-2, 6-2, while second seed Nikki Manalo claimed the girls’ 12-under title over fourth seed Trudy Amoranto, 6-2, 6-1.