The Lions survived a furious rally by the Mapua Cardinals as they eked out a come-from-behind 55-51 victory to make the finals for the first time since achieving the feat nine years ago.
The Dolphins, on the other hand, blasted the Letran Knights, 72-50, in the other semifinal contest to book their third straight championship appearance.
The title series starts on Monday also at the Big Dome.
"I thank Mapua for pushing us to the limit. The Cardinals were aggressive and they knew what to do," said San Beda coach Koy Banal.
The victory likewise stretched the Lions’ streak to 13, duplicating their longest run 28 years ago on their way to their last title conquest.
They could match the league’s longest streak of 14 games held by the Rommel Adducul-led San Sebastian Stags in 1997 if they take the series’ opener on Monday.
Yousif Aljamal fired 20 points, including seven in the fourth quarter as the Lions swept the Cardinals in three games this season.
Gabby Espinas, picked fifth overall by San Miguel Beer in this year’s PBA rookie draft, logged 16 points and 14 rebounds to help deal the Knights their worst beating this year.
Aaron Aban and Boyet Bautista, also set to be signed by Alaska Milk and Purefoods, finished 16 and 12 points, respectively for Letran.
"Even before this game, coach Louie (Alas) admitted that we have a deeper bench, and it showed in this game," said PCU mentor Joel Dualan, hoping to steer the school to its second title in three years.
Mapua, which lost by more than 15 twice to San Beda, came prepared against the Lions as it controlled the tempo majority of the game behind Joferson Gonzales and Kelvin dela Pena.
The Cardinals, however, failed to sustain their pace and collapsed at crunchtime.
In contrast, the Dolphins imposed their will on the Knights.
Robby David chipped in 15 points while Castro and Garrido added 10 apiece. The 6’4" Garrido, who saw little action last season because of a foot injury, also plucked 11 rebounds.