The APO golfers scored 96 points in their second trip at the short, but tricky course to forge ahead going into the last 36 holes at the Camp John Hay Golf Club.
Demi Saclot once again starred for APO, posting 30 points, the first player in the division to break the 30-point mark after two rounds.
Reynaldo Talatala and Querubin Alcantara added 24 and 23, respectively while Raul Lambino counted with 19 points.
APO now has 181 points, relegating Srixon IMG to second with 169.
Srixon was led by Francis Roger Telan who knocked in 24. He got support from August Cruz 21, Efren Leonardo 20 and Bernard Chang 19.
Manila Southwoods Team 2 dropped to third with 167 after pooling 80 points, including 22 from Thirdy Escano.
Other Southwoods scorers were Joseph Tambunting 21, Raulito Magpantay 20 and Ryan Abdon 17.
Dugong Bughaw and Megafiber rounded out the standings with 166 and 164, respectively.
The Fil and Am-Championship divisions take a break on Tuesday.
Elsewhere, Bibak NY/NJ Igolfers collected 79 points to retain the lead in the Senior Am-A class with 160, nine points clear of Pradera Verde and Baguio Blue Bloods who carded an 81 and 80, respectively.
In Senior Am-D, The Residences at Brent was on top with 122 followed by ICSI/TMI Team 2 with 110 and Sandigan Golfers Team 2 with 107.