University of Santo Tomas displayed tremendous mental toughness in hammering a heart-stopping five-set victory over Ateneo de Manila University in Season 86 University Athletic Association of the Philippines women's volleyball tournament late Wednesday.

UST coach Kungfu Reyes liked what he saw.

Reyes said staying composed in front of a massive crowd with the game on the line isn't easy but he is proud with how the Tigresses handled pressure, especially in the crucial stretch of the deciding set.

"We can't teach them the experience of playing in front of a big crowd and under a spotlight in practice. The games where they are pressured, they experienced it first-hand," Reyes said following their scary 25-15, 27-25, 23-25, 26-28, 15-13, win at the Smart Araneta Coliseum.

"The mental toughness, we develop that every game. It's a different story every game and in those games, we learn a lot."

Cassie Carballo, despite committing a service error late in the fourth set that nearly led to their first loss this season, displayed impressive grace under pressure as she bounced back from her miscue.

The sophomore setter tallied 26 excellent sets with 10 points highlighted by crucial aces that doomed the Blue Eagles' chances in the decider.

"That service error became my motivation because it was so crucial in the fourth set," Carballo said.

"I told myself that I need to trust myself to bounce back because my team needs me."

Despite the setback, Blue Eagles head coach Sergio Veloso remains proud of the performance of his young team.

"We started the second round by playing (against) one of the strongest teams, and my players showed that they can play at this level," the veteran Brazilian mentor said.

"I think today, they played one of their best matches."

Lyann De Guzman dropped 22 points as she served as the focal point of the Blue Eagles' offense in the final set before absorbing their sixth loss in eight matches.