Platinum whipped winless Zamboanga Valientes, 22-10, on Sunday for a 4-0 record and the top spot in Pool A.
Platinum is also the only undefeated team heading to the knockout stage.
Also progressing in the same group are Limitless Appmasters (3-1) and Cavitex (2-2).
In Pool B, Leg 2 winner Meralco and Pioneer Pro Tibay, earned outright quarterfinals berths after emerging as the two teams with the highest points in their group. Both teams along with San Miguel ended up in a triple-way tie at 2-1.
Terrafirma later completed the quarterfinals cast by outlasting undermanned San Miguel in overtime, 23-20.
The two teams met in a sudden-death after being relegated as the No. 3 teams in their respective pools.
Karl Dehesa and Platinum move on the round of eight.
The Dyip rallied back from a 14-18 deficit behind Dhon Reverente, Matt Salem, and Terrence Tumalip to force overtime, 20-all.
Reverente, who had a game-high 12 points, then scored the go-ahead basket in the extra period before Salem sealed the deal for the Dyip with a two.
The quarterfinals match up will have Meralco taking on Cavitex, Pioneer Pro Tibay against Purefoods TJ Titans, and TNT opposite Limitless Appmasters.
San Miguel lost Bacon Austria early in the game after suffering a bloodied lip courtesy of a wayward elbow of Reverente.
Terrafirma (23) – Reverente 12, Salem 6, Tumalip 5, Bulawan 0.
San Miguel (20) – Mangahas 8, Vigil 7, Manday 5, Austria 0.