Serranos explosive windup included seven points in the last three minutes of the contest, which the Eagles dominated in the early going but failed to sustain in the face of the Blades final quarter charge.
Top gun Eddie Laure had a struggling outing for the Blades while last years MVP Romel Adducul did not suit up due to an ankle injury he sustained in recent practice, but the visiting squad still managed to overcome the odds, including a sputtering start.
The win put the Blades at solo fourth spot with a 4-2 record while sending Davao, now coached by Jun Noel, at the bottom of the standing with a miserable 1-7 card.
Playing catch-up in the opening period and early in the next, the Blades put their act together bridging the second and third quarters to seize control, only to stagger again late in the period.
In the second game, FedEx Laguna notched its third win in six outings as it overwhelmed Nueva Ecija, 111-100, at the San Luis Sports Complex in Sta. Cruz, Laguna. It was the Patriots third loss against two triumphs.
That enabled the Eagles to tie the game at 62-all heading into the fourth but the Blades came through with a quick 9-3 run, behind Serranos Blitz 3, to open the period and another 71-64 lead.
Still, the Eagles, urged on by a boisterous crowd, countered with a stirring 11-0 run behind the guns of Michael Manigo and Ryan Bernardo as they wrested the lead at 75-71. But they celebrated early and flubbed a couple of offensive thrusts while failing to stop their rivals, particularly Serrano, on the other end of the floor.
The setback dropped the Eagles to 1-7.