Bautista fired his season-best 30 points including 21 from behind the arc as the Knights solidified their grip of the top spot with four straight wins.
"Hes the heart and soul of this team, Im always confident well pull through if hes around," said Letran coach Louie Alas of his 23-year-old pointguard, who is turning pro this year.
Bautista came to his teams rescue by scoring four points in an 8-0 splurge in the stretch that doused cold water on PCUs last-ditch effort to steal the win.
Down 40-52, Jason Castro sparked an 8-0 run as PCU clawed back to within four points midway in the final period but it turned out to be the teams last stand as Bautista entered the fray to defuse the Dolphins rally.
Gabby Espinas, the 2004 rookie MVP, had a solid 13-point, 15-rebound performance but he found little help from the rest of the Dolphins.
In the other seniors game, Mapua outgunned St. Benilde in a shootfest, 79-74, to remain inside the magic four with a 3-2 (win-loss) slate.
Castro, who missed the teams 81-77 win over Jose Rizal Monday because he had to attend to his ailing grandmother in Pampanga, struggled offensively and simply had no answer to Bautistas firepower.
The Amerasian from Lubao was good for only nine points after missing 11 of his 15 shots, one of the factors that sent the Dolphins to their second defeat after stringing up four wins in row.