Trier's performance is two days removed from a career-high 32 points. It was the second game that Arizona has surpassed 100 points.
In a fast-paced game, Arizona survived an early second-half surge by UMBC as the Retrievers (0-2) closed to within 58-55 in the first two minutes.
But Arizona (2-0) was able to get a double-digit lead at 78-63 with 9:32 left behind Trier's 15 second-half points.
The Retrievers continued to stay close early in the second half, using 3-pointers and attacking the basket.
That was when Arizona finally took control behind a 13-0 run, culminated by back-to-back 3-pointers by freshman guard Alex Barcello.
Arizona had slowly extended a double-digit before the big run behind 7-foot-1 Akon, who hit two 15-foot jumpers and blocked or altered shots. He put an exclamation point on the victory with a huge rebound dunk, making it 98-71 with 2:35 left.
Arizona's Keanu Pinder followed it with a blocked shot where the ball landed about 10 rows into the stands.
Each team couldn't be stopped on the perimeter with Arizona hitting 15 of 27 3 pointers. UMBC hit 14 of 28.
UMBC's Jairus Lyles had a game-high 31 points, 23 coming in the first half. He was 5 of 8 from beyond the arc.
Arizona was down 11-5 early in the game, but went on a 15-0 run to take control of the first half behind Trier and Akot. And later extended it to a 24-3 run with the highlight coming from Akot on an alley-oop dunk to make it 31-16.
However, UMBC stayed close throughout the first half by hitting 3s and improbable shots against the taller Wildcats.
Arizona shot 70 percent from the floor in the first half.
NOTES: Arizona freshman Brandon Randolph played his first game of his career after dealing with concussion issues the last week. He missed Friday night's game. ... Sophomore transfer G Dylan Smith played in his first game after sitting out the first game because of a team violation. ... Senior F Keanu Pinder played his first game after having to sit out the first game because of an NCAA violation. ... This was UMBC's first meeting with Arizona ... The loss will prevent UMBC from equaling last season's start of 7-1, which was a school best.