MANILA, Philippines -- With their backs against the wall, Ateneo de Manila University delivered the biggest upset of the UAAP Season 85 High School Boys' Basketball Tournament, ending Adamson University's 11-game winning streak with a 58-55 stunner, Saturday at Paco Arena.

Even with the win that improved their record to 5-8, the Blue Eagles' Final Four chances are no longer in their hands. They hope that University of Santo Tomas loses to University of the Philippines Integrated School later in the day and to the Soaring Falcons on Wednesday while also winning their rivalry game against De La Salle Zobel also on Wednesday.

Despite the predicament they are in, Ateneo High head coach Reggie Varilla is just proud of the stand they put up against the erstwhile-league leaders.

"More than the game... Kasi we had a rough week this week, my brother-in-law passed away last Wednesday. They wanted to win the game versus UST for me. Pero sabi ko naman sa kanila, win or lose, just do your best. Finally, the boys got rewarded," said an emotional Varilla.

With just 30 seconds left in the game, Peter Rosillo was able to find Mat Edding for a clean jumper to give Adamson a 55-54 lead.

A miss from Jordan Salandanan from deep was rebounded by Lebron Nieto. Nieto was fouled on a putback attempt by Edding, sending him to the line with eight ticks remaining.

The Grade 12 guard nailed both of his free throws to put Ateneo up.

"Ako kasi, lagi ako nagsi-simulate sa practice for free throws, up one or down one. So ginawa ko lang yung pinractice ko," recalled Nieto.

Off a timeout, Rosillo went for the quick shot but missed. Again, Nieto went to the stripe, extending Ateneo's lead to three with 1.8 seconds left on the clock.

With no timeouts, Rosillo went for a hail mary but missed as their top seed hopes are now in peril heading into the final game day on Wednesday at the Filoil Ecooil Centre.

"We just hope for the best," said Varilla.

Nieto produced 19 points, six steals, five rebounds, and five assists while Grade 11, Cebuano big man Kristian Porter got 17 points and 20 rebounds.

Vince Reyes paced the Baby Falcons with 19 points while Edding added 14 points and nine rebounds.

Ateneo limited Rosillo to just eight points on 3-of-12 shooting from the field.

Ateneo's win gave Far Eastern University-Diliman and Nazareth School of National University an unlikely assist as well.

Earlier, the Baby Tamaraws ripped also-ran University of the East, 96-87.

JR Pasaol, a grade 12 guard, broke out of his slump for FEU-D, producing 24 points, six rebounds, six assists, and three steals.

The frontcourt of Kirby Mongcopa and VJ Pre also delivered with the former notching a double-double with 19 points and 13 rebounds while the latter chipping in 10 points and six boards.

FEU-D and Adamson are now tied atop of the standings with identical 11-2 slates. NSNU can join in the fray if it eliminates DLSZ, later in the day.

Drei Gragasin and Martin Pangilinan were the bright spots for the Junior Warriors. Gragasin nailed three triples for 14 points while Pangilinan had 10 points and 12 rebounds.

The Scores:

First Game

FEU-D 96 - Pasaol 24, Mongcopa 19, Pre 10, Pascual 9, Salangsang 8, Cabonillas 7, Miranda 5, Daa 5, Felipe 4, Herbito 3, Burgos 2, Baricaua 0, Castillejos 0, Cabigting 0.

UE 87 - Gragasin 14, Pangilinan 10, Roldan 10, Malonzo 8, Caldit 8, Bagro 7, Reyes 7, Flores 6, Duque 5, De Leon 5, Gatchalian 4, Reyes 3, Isip 0, Morales 0, Ramos 0.

Quarterscores: 25-16, 55-33, 79-56, 96-87.

Second Game:

Ateneo 58 - Nieto 19, Porter 17, Adevoso 6, Fidel 5, De Guzman 3, Santiago 2, Arada 2, Aguirre 2, Domangcas 2, Urbina 0, Prado 0, Ebdane 0, Salandanan 0.

AdU 55 - Reyes 19, Edding 14, Rosillo 8, Bonzalida 4, Medina 3, Perez 3, Abayon 2, Carillo 2, Culdora 0, Sajili 0, Mepana 0, De Jesus 0, De Guzman 0, Tambauan 0.

Quarterscores: 15-11, 27-28, 43-40, 58-55.