Olongapo Citys Patrick John Tierro got a free ride to the quarters when Owen Ramos and Hans Prudencio failed to show up.
Earlier, Legaspi Citys Catherine Flores and Davaos Arra Micayabas scored similar wins to reach the girls 18-under quarterfinals division in this Group 1 event presented by Coca-Cola Bottlers Inc. and supported by Subic Bay Metropolitan Authority (SBMA) chairman Felicito Payumo.
Flores defeated Davao Citys Jessica Haro, 6-3, 6-2, to advance against Davao Orientals Jasper Joy Cabisong, a 6-2, 6-1 winner over Gabrielle Bautista.
Micayabas downed May Herrera, 6-2, 6-3, to advance against Camille Espiritu, who rallied past Ma. Angelica Ngo, 5-7, 6-3, 6-3.
Boys 16-under top seed Jandrick de Castro of La Salle-Greenhills, No. 3 Michael Basco of Letran, Oswaldo Dumoran of Cebu and Mauric Lao of Aklan also gained quarterfinal berths in this netfest sponsored by PLDT, Truflex, Union Bank, Union Cement, Wilson, Prince, Dunlop and Adidas.
De Castro blasted Alexis Lapaz, 6-0, 6-0; Basco defeated Hamza Macapendeg, 6-3, 3-6, 6-2; Dumoran outclassed Marie Justin Elesis, 6-1, 6-1; and Lao downed Perene Alina, 7-5, 6-1. Other winners were Michael Paynor, Miguel Narvaez and Victor Ronell Javier.
Booking quarterfinal slots in the girls 14-under were Macy Serrano of Davao Oriental, Juneiza Galinato of Sultan Kudarat, Jin Querubin of Cebu and Branda Claire Noquillo while in the girls 12-under class were No. 1 Jessica Agra, No. 2 Bambi Zoleta, Nikki Manalo, Jecille Ortillano, Martina Guba, Sally Mae Siso and Jumelsa Galinato.
First-round winners were Ivan Joshua Manalo, Gian Paolo Aguila and Hussein Macapendeg in the boys 14-under; Joman Narvaez, Omar Khalil Tayag and El Santo Santos in the boys 12-under; and Maika Jae Tanpoco, Cristina Abrot, Angelo Joseph Rivero and Mary Grace Rivero in the unisex 10-under.