ARELLANO University stunned defending champion San Beda University after a hard-fought 72-70 win in the NCAA Season 100 men's basketball tournament at the FilOil EcoOil Center in San Juan City on Saturday.

Sophomore Ernjay Geronimo showed composure in the last stretch of the quarter to lead the Chiefs and tallied his career-high performance of 12 points, four rebounds and three assists.

San Beda held a 64-61 lead in the last five minutes of the final frame, but Chief Renzo Abiera fired a triple to send the match to its 10th deadlock.

Jomel Puno was hot beyond the arch and drained his fourth three-pointer in the match, but Geronimo answered back with a layup to answer back on the Red Lions' offense, 67-66.

Geronimo once more stormed the defense of the Red Lions and drove to the basket, completing his and-one play that gave Arellano that two-point advantage, 69-67.

In the last two minutes of the final canto, San Beda kept firing blanks from the outside as Bryan Sajonia, James Payosing, Yukien Andrada and Jomel Puno struggled to convert a field goal.

With the Red Lions already in the penalty, Payosing made a crucial foul on Abiera, on which Abiera scored one out of two of his freebies, 70-67.

The Chiefs widened the gap in the last 44.7 seconds as Lorenz Capulong put up a one-handed shot that gave the Chiefs the crucial lead, 72-67.

Andrada scored his first triple in the match with 37.5 seconds remaining, allowing the match to be a one-possession game, 72-70.

But the Chiefs played hard on their defense, and the clock did not favor the Red Lions.

"Of course, the target is the champion team, so that we can test our program and our capabilities. It is evident that the team really worked hard, from the coaches to the players. Maybe we are lucky today, and this is my team's birthday gift to me," head coach Chico Manabat told the press after the game.

The Chiefs overcame a 13-point deficit in the opening canto, 32-19, and took over in the second quarter after a 17-2 rampage to end the first half leading, 36-32.

Arellano spoiled Jomel Puno's career-high performance of 20 points, six rebounds, two assists and two steals.

Arellano captured its second win in the tournament and tallied a 2-5 slate, while San Beda fell to 3-3.