Earlier, Mapua shocked defending champion Letran, 54-49, to complete the Final Four cast.
The Lions got a big break when the Dolphins lost their poise after coach Joel Dualan was thrown out of the game early in the fourth quarter on technical fouls for repeatedly contesting referees’ calls. They went on to post their 10th straight win and their 11th in 12 outings.
San Beda, thus, assured itself of one of two top berths with two more assignments on tap in the double-round eliminations.
"I’ve learned through years of coaching not to use vengeance to motivate the team. We focused on clinching twice-to-beat incentive," said San Beda coach Koy Banal as they avenged their 66-70 loss to PCU in the first round.
Yousif Aljamal scored 14 points while Nigerian behemoth Samuel Ekwe made 13 points, 11 rebounds and three blocks to lead San Beda onslaught.
The Dolphins suffered a fourth loss against eight wins. Worse, they may play the next game with their coach serving a suspension.
Kelvin dela Peña, last season’s rookie of the year, came through with his biggest game so far as he dished out 20 points including seven each in the final two quarters.
Mapua clinched the last slot in the semis on its seventh win against five defeats.
"Since I started coaching Mapua, we always beat Letran at least once each year. That’s why I was confident we would win today," said Mapua mentor Horacio Lim.
The Knights struggled all game as they muffed 49 of their 70 attempts including 23 misses from behind the arc.
Pro-bound Aaron Aban and Boyet Bautista, picked seventh and ninth overall, respectively, in last Sunday’s PBA draft, were the only Knights who finished with double digit scores with 11 and 10 points.