Fonacier, who also had a big hand in Ateneos title victory by hitting crucial baskets in the PBL Challenge Cup last month, was left wide open twice in the extra period. He made the Tamaraws pay dearly for it with his last triple giving the Eagles a 71-68 with two minutes left.
The two teams then bungled their next offensive thrusts before Wesley Gonzales broke the silence, scoring on a short jumper with only two ticks left and sealing the Eagles third win in as many games for a tie with archrival La Salle.
Fonacier shot poorly in regulation but more than made up for it by scoring eight of his 14 points in overtime. Gonzales topscored for Ateneo with 16 points while starters Enrico Villanueva, Rich Alvarez and LA Tenorio each scored 12 points or more.
"Larry Fonacier played so-so in four quarters but he hit the shots that spelled victory for us in overtime," said Ateneo coach Joel Banal whose younger brother Coy called the shot for the Tamaraws.
Earlier, Santo Tomas blew hot and cold as it hacked a 92-75 victory over University of the Philippines. It was the second win in three outings for the Tigers while the loss was the second straight for the Maroons after an opening-day win over the UE Warriors.
The Tigers, winner of four straight titles , the last in 1996, erected a 50-31 lead in the second quarter before Michael Bravo waxed hot for UP as he helped cut the lead to 52-56. But he was pulled out by coach Allan Gregorio, allowing the Tigers to finally settle the issue, 77-58.