Filipino International Master Daniel Quizon delivered the biggest shocker of the MPCL's Manny Pacquiao International Open Chess Festival in General Santos City to date after bringing down third seed Vitaly Sivuk of Sweden Thursday.

The 18-year-old Hanoi Southeast Asian Games bronze medalist from Dasmariñas, Cavite, unleashed the King's Indian Defense on the 30-year-old Sivuk and emerged victorious in their razor-sharp duel in 41 moves to bolster his title chances.

The huge victory catapulted Quizon to a six-man tie at third with four points apiece, or just half a point behind co-leaders GMs Hovhannes Gabuzyan of Armenia and Lucas Van Foreest of the Netherlands each with 4.5 points.

Gabuzyan and Van Foreest halved the point to stay at the helm in this tournament staking a champion's purse amounting to a whopping P1.14 million, the biggest in the country in recent years.

Quizon, for his part, was bunched with fourth pick Pier Luigi Basso of Italy, IM John Daniel Bryant of the United States and Filipino IMs Kim Steven Yap and Ricky de Guzman.

Basso smashed IM Cris Ramayrat; Bryant trounced Sherwin Tiu; Yap tripped GM Darwin Laylo; and De Guzman stunned GM John Paul Gomez.

In another pack at No. 9 with 3.5 points were Russian-born FIDE-represented Konstantin Sek, IM Richilieu Salcedo, IM Michael Concio Jr., FIDE Master Mari Joseph Turqueza, IM Eric Labog Jr., Sheider Nebato and GM Joey Antonio.

Quizon will try to catch a bigger fish as he was battling the top-ranked Gabuzyan in the sixth round at press time and boost his chances of earning the second of three norms to claim the GM title in this nine-round tilt backed by President Ferdinand "Bongbong" Marcos Jr., the National Chess Federation of the Philippines, Philippine Sports Commission and Philippine Olympic Committee.