Cabahug advanced to the quarterfinal after he clobbered Ramesis Rey Rivera, 6-0, 6-1 while Du stopped Sheena Tabo in straight sets, 6-3, 6-1.
But Du will have to be extra careful as she battles out the no.1 seeded player Krystel Mae Buenacosa in her next assignment.
Cabahug, on the other hand, will be facing the winner between the Joseph Tallo and Bryan Mangapis.
Cabahug's twin, Christian Paul, seeded fourth, will be battling in the round of 16 today against Joel Tabo.
Tabo stepped into the next round after defeating John Rey Boricano, 6-4, 6-3.
Another player barging into the round of 16 is University of the Visayas' Ryan Repunte after he smashed Kenneth Lim, 6-3, 6-1, in the boys' 21-under class.
With the win, Repunte is set to face next seeded no. 4 Dandreb Donio of the University of San Carlos.
Tournament director Fritz Tabura is positive action will go full-blast today.