The Lady Archers stamped their class early, taking the first two sets in lopsided fashions before overcoming a tough resistance by the Lady Pirates in the third set to complete the straight-set victory.
Skipper Desiree Hernandez and Thai import Jindarat Kinchana led the attack with 13 hits apiece while comely Michelle Datuin added 12 to send the Taft-based school closer to clinching a fourth straight finals appearance in this tournament presented by Shakeys Pizza and organized by Sports Vision.
San Sebastian stepped up its finals bid by outlasting Adamson, 25-19, 25-27, 27-25, 25-18, in the second game to notch its sixth victory against four losses.
The win, their second in the semis, enabled the Lady Stags to close in on their victim, who fell to their third loss in nine games.
La Salles hot start against Lyceum was in stark contrast to its sputtering stint against San Sebastian last week where the Lady Archers dropped the first two sets before sweeping the next three, 21-25, 23-25, 25-9, 25-21, 15-5.
"We adjusted on our reception game and our service because we did bad in both in our last game against San Sebastian," said La Salle coach Ramil de Jesus, who steered the school to three straight UAAP titles, in Filipino.
"We also warmed up longer today (yesterday) compared to last time," added the soft-spoken mentor.
Con Con Legaspi, who helped La Salle win last conferences title, led all hitters with 14 points, the bulk of which coming in the third set when she tried but failed to help Lyceum force an extra set.
Shackled up front, the power-hitting Legaspi broke through La Salles tight net defense by pounding in kills one after another as the Lady Pirates kept the game close.
But Ponchana, one of the two Thais seeing action in this tournament backed by Accel, Mikasa, Vfresh, Aquabest, ABC-5 and ABC Sports, countered with her own array of spikes to take the fight out of Emil Lontocs charges.
It was Lyceums sixth loss against four wins, needing to sweep its last five games to avail itself of the leagues 5-of-8 incentive rule for a playoff for the second finals berth.