Shaman, mentored by Wawa Justalero, led most of the way and even maintained a five-point edge, 73-68, at the 7:44 mark of the fourth period, but Inayawan was poised to steal the win when Michael Arias scored the go-ahead basket, 80-79, with :14 left in the game.
Power 40 was going for the insurance basket in a crucial possession, but was whistled for a 24-second infraction.
Dodong Astida then used his height advantage with authority as the 6-2 center-forward converted an undergoal stab that sealed Shaman's victory with 15 ticks before the final buzzer.
Astida finished with 10 points, although it was Arlow Estrellado and Bobot Eran led Shaman's offense with 18 and 16 points, respectively. Doods Sarming was the other Dumaguete cager who finished in double figures with 13.
Atty. Flor Yosores, who sponsored the goodwill encounter, had 15 points spiked with five 3-pointers. His third triple gave Power 40 a 62-61 lead, but Sarming and Eran scored six straight points for a 67-62 reversal in favor of Sharma.
It was ex-SWU Cobra Carding Vernaiz who led Power 40 with 18 points. Arias chipped in 12 markers.
The scores
Shaman (81) - Estrellado 18, Eran 16, Sarming 13, Astida 10, Uy 5, Justalero 4, Cornelia 4, Remata 3, Duran 3, Anataro 2, Casas 2, Garovillo 2, Estrosos 1
Power 40 (80) - Vernaiz 18, Yosores 15, Arias 12, Rosal 9, Yu 5, Rabaya 4, Dumali 4, Javierto 3, Dejarme 2, Abasolo 2, Eleguin 2 Halftime: 53-48