CIGNAL-Ateneo blasted McDavid, 106-31, Tuesday in the 2019 PBA D-League Tuesday at JCSGO Gym in Cubao.
McDavid's total output of 31 points erased the previous low when PC Gilmore lost to Boracay Rum, 71-41,back in Jan. 10, 2012.
Ivorian center Ange Kouame tallied a double-double with 16 points and 14 rebounds for the Blue Eagles, whose 75 point winning margin was one-point short of tying the league record.
Thirdy Ravena was as impressive with 16 points and three rebounds, while Mike Nieto led a strong start by Cignal-Ateneo by pouring all his 11 points in the first half.
Cignal-Ateneo improved to 6-1 record to stay at the top of the Aspirants Group.
As potent as Ateneo's offense was its defense which held the opposition to just 21-percent field goal shooting.
The record for the largest winning margin is 76-points when Tanduay topped Zark's Burgers, 141-65, back in July 10, 2017.
Cignal-Ateneo put the outcome beyond recall early when it build a 31-6 advantage.
"As you go through a year, an offseason, a preseason campaign, your system should grow," Ateno coach Tab Baldwin said.
"Today, we did use a couple of different things that we may or may not use but we teach our players some things that they can have in their arsenal. We may not run it very well but we're exposing them in different types of offensive and defensive systems."
Marlon Monte topscored for McDavid (1-5) with 11 points.
CIGNAL-ATENEO 106 -- Kouame 16, Ravena 16, Mi. Nieto 11, Berjay 9, Go 8, Daves 8, Credo 8, Ma. Nieto 6, Tio 6, Navarro 6, Mamuyac 4, Wong 3, Andrade 3, Belangel 2.
MCDAVID 31 -- Monte 11, Diputado 6, Gaco 6, Lozada 3, Sorela 3, Melano 2, Canada 0, Escosio 0, Colina 0.
Quarters: 31-5, 57-15, 90-28, 106-31.